Microprocessor and Interfacing Free Essays

string(187) " the control register and all ports are set to the input mode e\) A0 and A1 \( Address pins \): These pins in conjunction with RD and WR pins control the selection of one of the 3 ports\." UNIT II- Peripherals and Interfacing PIO 8255 The parallel input-output port chip 8255 is also called as programmable peripheral input-output port. The Intel’s 8255 is designed for use with Intel’s 8-bit, 16-bit and higher capability microprocessors. It has 24 input/output lines which may be individually programmed in two groups of twelve lines each, or three groups of eight lines. We will write a custom essay sample on Microprocessor and Interfacing or any similar topic only for you Order Now The two groups of I/O pins are named as Group A and Group B. Each of these two groups contains a subgroup of eight I/O lines called as 8-bit port and another subgroup of four lines or a 4-bit port. Thus Group A contains an 8-bit port A along with a 4-bit port. C upper. PIO 8255 †¢ The port A lines are identified by symbols PA0-PA7 while the port C lines are identified as PC4-PC7. Similarly, GroupB contains an 8-bit port B, containing lines PB0-PB7 and 4-bit port C with lower bits PC0- PC3. The port C upper and port C lower can be used in combination as an 8-bitport C. †¢ Both the port C are assigned the same address. Thus one may have either three 8-bit I/O ports or two 8-bit and two 4-bit ports from 8255. All of these ports can function independently either as input or as output ports. This can be achieved by programming the bits of an internal register of 8255 called as control word register ( CWR ). PIO 8255 †¢ The internal block diagram and the pin configuration of 8255 are shown in fig. †¢ The 8-bit data bus buffer is controlled by the read/write control logic. The read/write control logic manages all of the internal and external transfers of both data and control words. †¢ RD, WR, A1, A0 and RESET are the inputs provided by the microprocessor to the READ/ WRITE control logic of 8255. The 8-bit, 3-state bidirectional buffer is used to interface the 8255 internal data bus with the external system data bus. PIO 8255 †¢ This buffer receives or transmits data upon the execution of input or output instructions by the microprocessor. The control words or status information is also transferred through the buffer. †¢ The signal description of 8255 are briefly presented as follows : †¢ PA7-PA0: These are eight port A lines that acts as either latched output or buffered input lines depending upon the control word loaded into the control word register. †¢ PC7-PC4 : Upper nibble of port C lines. They may act as either output latches or input buffers lines. PIO 8255 This port also can be used for generation of handshake lines in mode 1 or mode 2. †¢ PC3-PC0 : These are the lower port C lines, other details are the same as PC7-PC4 lines. †¢ PB0-PB7 : These are the eight port B lines which are used as latched output lines or buffered input lines in the same way as port A. †¢ RD : This is the input line driven by the microprocessor and should be low to indicate read operation to 8255. †¢ WR : This is an input line driven by the microprocessor. A low on this line indicates write operation. PIO 8255 †¢ CS : This is a chip select line. If this line goes low, it enables the 8255 to respond to RD and WR signals, otherwise RD and WR signal are neglected. †¢ A1-A0 : These are the address input lines and are driven by the microprocessor. These lines A1-A0 with RD, WR and CS from the following operations for 8255. These address lines are used for addressing any one of the four registers, i. e. three ports and a control word register as given in table below. †¢ In case of 8086 systems, if the 8255 is to be interfaced with lower order data bus, the A0 and A1 pins of 8255 are connected with A1 and A2 respectively. RD 0 0 0 0 RD 1 1 1 1 RD X 1 WR 1 1 1 1 WR 0 0 0 0 WR X 1 CS 0 0 0 0 CS 0 0 0 0 CS 1 0 A1 0 0 1 1 A1 0 0 1 1 A1 X X A0 0 1 0 1 A0 0 1 0 1 A0 X X Input (Read) cycle Port A to Data bus Port B to Data bus Port C to Data bus CWR to Data bus Output (Write) cycle Data bus to Port A Data bus to Port B Data bus to Port C Data bus to CWR Function Data bus tristated Data bus tristated Control Word Register PIO 8255. †¢ D0-D7 : These are the data bus lines those carry data or control word to/from the microprocessor. †¢ RESET : A logic high on this line clears the control word register of 8255. All ports are set as input ports by default after reset. Block Diagram of 8255 (Architecture) ( cont.. ) †¢ 1. 2. 3. 4. †¢ It has a 40 pins of 4 groups. Data bus buffer Read Write control logic Group A and Group B controls Port A, B and C Data bus buffer: This is a tristate bidirectional buffer used to interface the 8255 to system databus. Data is transmitted or received by the buffer on execution of input or output instruction by the CPU. Control word and status information are also transferred through this unit. †¢ Block Diagram of 8255 (Architecture) ( cont.. ) Read/Write control logic: This unit accepts control signals ( RD, WR ) and also inputs from address bus and issues commands to individual group of control blocks ( Group A, Group B). †¢ It has the following pins. a) CS – Chipselect : A low on this PIN enables the communication between CPU and 8255. b) RD (Read) – A low on this pin enables the CPU to read the data in the ports or the status word through data bus buffer. †¢ Block Diagram of 8255 (Architecture) ( cont.. ) WR ( Write ) : A low on this pin, the CPU can write data on to the ports or on to the control register through the data bus buffer. ) RESET: A high on this pin clears the control register and all ports are set to the input mode e) A0 and A1 ( Address pins ): These pins in conjunction with RD and WR pins control the selection of one of the 3 ports. You read "Microprocessor and Interfacing" in category "Papers" †¢ Group A and Group B controls : These block receive control from the CPU and iss ues commands to their respective ports. c) Block Diagram of 8255 (Architecture) ( cont.. ) †¢ Group A – PA and PCU ( PC7 -PC4) †¢ Group B – PCL ( PC3 – PC0) †¢ Control word register can only be written into no read operation of the CW register is allowed. a) Port A: This has an 8 bit latched/buffered O/P and 8 bit input latch. It can be programmed in 3 modes – mode 0, mode 1, mode 2. b) Port B: This has an 8 bit latched / buffered O/P and 8 bit input latch. It can be programmed in mode 0, mode1. Block Diagram of 8255 (Architecture). c) Port C : This has an 8 bit latched input buffer and 8 bit out put latched/buffer. This port can be divided into two 4 bit ports and can be used as control signals for port A and port B. it can be programmed in mode 0. Modes of Operation of 8255 (cont.. ) †¢ These are two basic modes of operation of 8255. I/O mode and Bit Set-Reset mode (BSR). †¢ In I/O mode, the 8255 ports work as programmable I/O ports, while in BSR mode only port C (PC0-PC7) can be used to set or reset its individual port bits. †¢ Under the I/O mode of operation, further there are three modes of operation of 8255, so as to support different types of applications, mode 0, mode 1 and mode 2. Modes of Operation of 8255 (cont.. ) †¢ BSR Mode: In this mode any of the 8-bits of port C can be set or reset depending on D0 of the control word. The bit to be set or reset is selected by bit select flags D3, D2 and D 1 of the CWR as given in table. I/O Modes : a) Mode 0 ( Basic I/O mode ): This mode is also called as basic input/output mode. This mode provides simple input and output capabilities using each of the three ports. Data can be simply read from and written to the input and output ports respectively, after appropriate initialisation. D3 0 0 0 0 1 1 1 1 D2 0 0 1 1 0 0 1 1 D1 0 1 0 1 0 1 0 1 Selected bit s of port C D0 D1 D2 D3 D4 D5 D6 D7 BSR Mode : CWR Format PA 8 2 5 5 PCU PCL PA6 – PA7 PC4 – PC7 PC0-PC3 PB PB0 – PB7 8 2 5 5 PA PCU PCL PB PA PC PB0 – PB7 All Output Port A and Port C acting as O/P. Port B acting as I/P Mode 0 Modes of Operation of 8255 (cont.. ) †¢ 1. The salient features of this mode are as listed below: Two 8-bit ports ( port A and port B )and two 4-bit ports (port C upper and lower ) are available. The two 4-bit ports can be combinedly used as a third 8-bit port. Any port can be used as an input or output port. Output ports are latched. Input ports are not latched. A maximum of four ports are available so that overall 16 I/O configuration are possible. All these modes can be selected by programming a register internal to 8255 known as CWR. 2. 3. 4. †¢ Modes of Operation of 8255 (cont.. †¢ The control word register has two formats. The first format is valid for I/O modes of operation, i. e. modes 0, mode 1 and mode 2 while the second format is valid for bit set/reset (BSR) mode of operation. These formats are shown in following fig. D7 1 D6 X D5 X D4 X D3 D2 D1 D0 0- Reset 0-for BSR mode Bit select flags D3, D2, D1 are from 000 to 111 for bits PC0 TO PC71- Set I/O Mode Control Word Register Format and BSR Mode Control Word Register Format PA3 PA2 PA1 PA0 RD CS GND A1 A0 PC7 PC6 PC5 PC4 PC0 PC1 PC2 PC3 PB0 PB1 PB2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 0 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 PA4 PA5 PA6 PA7 WR Reset D0 D1 D2 D3 D4 D5 D6 D7 Vcc PB7 PB6 PB5 PB4 PB3 8255A 8255A Pin Configuration = D0-D7 CS RESET 8255A A0 A1 RD PA0-PA7 PC4-PC7 PC0-PC3 PB0-PB7 Vcc WR GND Signals of 8255 3 Group A control 1 D0-D7 Data bus Buffer 8 bit int data bus 4 Group A Port A(8) PA0-PA7 Group A Port C upper(4) Group B Port C Lower(4) PC7-PC4 PC0-PC3 2 RD WR A0 A1 RESET CS Block Diagram of 8255 READ/ WRITE Control Logic Group B control PB7-PB0 Group B Port B(8) D7 D6 D5 Mode for Port A D4 PA D3 PC U D2 Mode for PB D1 PB D0 PC L Mode Set flag 1- active 0- BSR mode Group – A 1 Input PC u 0 Output 1 Input PA 0 Output 00 – mode 0 Mode 01 – mode 1 Select of PA 10 – mode 2 Group – B PCL PB Mode Select 1 Input 0 Output 1 Input 0 Output 0 mode- 0 1 mode- 1 Control Word Format of 8255 Modes of Operation of 8255 (cont.. ) b) Mode 1: ( Strobed input/output mode ) In this mode the handshaking control the input and output action of the specified port. Port C lines PC0-PC2, provide strobe or handshake lines for port B. This group which includes port B and PC0-PC2 is called as group B for Strobed data input/output. Port C lines PC3-PC5 provide strobe lines for port A. This group including port A and PC3-PC5 from group A. Thus port C is utilized for generating handshake signals. The salient features of mode 1 are listed as follows: Modes of Operation of 8255 (cont.. ) 1. 2. 3. 4. Two groups – group A and group B are available for strobed data transfer. Each group contains one 8-bit data I/O port and one 4-bit control/data port. The 8-bit data port can be either used as input and output port. The inputs and outputs both are latched. Out of 8-bit port C, PC0-PC2 are used to generate control signals for port B and PC3-PC5 are used to generate control signals for port A. he lines PC6, PC7 may be used as independent data lines. Modes of Operation of 8255 (cont.. ) †¢ The control signals for both the groups in input and output modes are explained as follows: Input control signal definitions (mode 1 ): †¢ STB( Strobe input ) – If this lines falls to logic low level, the data available at 8-bit input port is loaded into input latche s. †¢ IBF ( Input buffer full ) – If this signal rises to logic 1, it indicates that data has been loaded into latches, i. e. it works as an acknowledgement. IBF is set by a low on STB and is reset by the rising edge of RD input. Modes of Operation of 8255 (cont.. ) †¢ INTR ( Interrupt request ) – This active high output signal can be used to interrupt the CPU whenever an input device requests the service. INTR is set by a high STB pin and a high at IBF pin. INTE is an internal flag that can be controlled by the bit set/reset mode of either PC4 (INTEA) or PC2(INTEB) as shown in fig. †¢ INTR is reset by a falling edge of RD input. Thus an external input device can be request the service of the processor by putting the data on the bus and sending the strobe signal. Modes of Operation of 8255 (cont.. Output control signal definitions (mode 1) : †¢ OBF (Output buffer full ) – This status signal, whenever falls to low, indicates that CPU has written data to the specified output port. The OBF flip-flop will be set by a rising edge of WR signal and reset by a low going edge at the ACK input. †¢ ACK ( Acknowledge input ) – ACK signal acts as an acknowledgement to be given by a n output device. ACK signal, whenever low, informs the CPU that the data transferred by the CPU to the output device through the port is received by the output device. Modes of Operation of 8255 (cont.. ) †¢ INTR ( Interrupt request ) – Thus an output signal that can be used to interrupt the CPU when an output device acknowledges the data received from the CPU. INTR is set when ACK, OBF and INTE are 1. It is reset by a falling edge on WR input. The INTEA and INTEB flags are controlled by the bit set-reset mode of PC 6and PC2 respectively. 1 0 1 0 Input control signal definitions in Mode 1 1/0 X X X 1 X X X X 1 1 X D7 D6 D5 D4 D3 D2 D1 D0 1 – Input 0 – Output For PC6 – PC7 PA0 – PA7 INTEA PC4 PC5 STBA IBFA D7 D6 D5 D4 D3 D2 D1 D0 PB0 – PB7 INTEB PC 2 PC1 STBB IBFB PC3 RD PC6 – PC7 INTRA I/O PC0 INTR A Mode 1 Control Word Group A I/P RD Mode 1 Control Word Group B I/P STB IBF INTR RD DATA from Peripheral Mode 1 Strobed Input Data Transfer WR OBF INTR ACK Data OP to Port Mode 1 Strobed Data Output Output control signal definitions Mode 1 1 0 1 0 1/0 X X X 1 X X X X 1 0 X D7 D6 D5 D4 D3 D2 D1 D0 1 – Input 0 – Output For PC4 – PC5 PA0 – PA7 INTEA PC7 PC6 OBF ACKA D7 D6 D5 D4 D3 D2 D1 D0 PB0 PB7 INTEB PC PC2 1 OBFB ACKB PC3 WR PC4 – PC5 PC0 INTRA I/O INTRB Mode 1 Control Word Group A Mode 1 Control Word Group B Modes of Operation of 8255 (cont.. ) †¢ Mode 2 ( Strobed bidirectional I/O ): This mode of operation of 8255 is also called as strobed bidirectional I/O. This mode of operation provides 8255 with an additional features for communicating with a peripheral device on an 8-bit data bus. Handshaking signals are provided to maintain proper data flow and synchronization between the data transmitter and receiver. The interrupt generation and other functions are similar to mode 1. †¢ In this mode, 8255 is a bidirectional 8-bit port with handshake signals. The RD and WR signals decide whether the 8255 is going to operate as an input port or output port. Modes of Operation of 8255 (cont.. ) †¢ 1. 2. 3. 4. 5. The Salient features of Mode 2 of 8255 are listed as follows: The single 8-bit port in group A is available. The 8-bit port is bidirectional and additionally a 5-bit control port is available. Three I/O lines are available at port C. ( PC2 – PC0 ) Inputs and outputs are both latched. The 5-bit control port C (PC3-PC7) is used for generating / accepting handshake signals for the 8-bit data transfer on port A. Modes of Operation of 8255 (cont.. ) †¢ Control signal definitions in mode 2: †¢ INTR – (Interrupt request) As in mode 1, this control signal is active high and is used to interrupt the microprocessor to ask for transfer of the next data byte to/from it. This signal is used for input ( read ) as well as output ( write ) operations. †¢ Control Signals for Output operations: †¢ OBF ( Output buffer full ) – This signal, when falls to low level, indicates that the CPU has written data to port A. Modes of Operation of 8255 (cont.. ) ACK ( Acknowledge ) This control input, when falls to logic low level, acknowledges that the previous data byte is received by the destination and next byte may be sent by the processor. This signal enables the internal tristate buffers to send the next data byte on port A. †¢ INTE1 ( A flag associated with OBF ) This can be controlled by bit set/reset mode with PC6 . †¢ Control signals for input operations : †¢ STB (Strobe input ) A low on this line is used to strobe in the data into the input latches of 8255. Modes of Operation of 8255 (cont.. ) †¢ IBF ( Input buffer full ) When the data is loaded into input buffer, this ignal rises to logic ‘1’. This can be used as an acknowledge that the data has been received by the receiver. †¢ The waveforms in fig show the operation in Mode 2 for output as well as input port. †¢ Note: WR must occur before ACK and STB must be activated before RD. WR OBF INTR ACK STB IBF Data bus RD Mode 2 Bidirectional Data Transfer Data from 8085 Data towards 8255 Modes of Operation of 8255 (cont.. ) †¢ The following fig shows a schematic diagram containing an 8-bit bidirectional port, 5-bit control port and the relation of INTR with the control pins. Port B can either be set to Mode 0 or 1 with port A( Group A ) is in Mode 2. Mode 2 is not available for port B. The following fig shows the control word. †¢ The INTR goes high onl y if either IBF, INTE2, STB and RD go high or OBF, INTE1, ACK and WR go high. The port C can be read to know the status of the peripheral device, in terms of the control signals, using the normal I/O instructions. D7 1 D6 1 D5 X D4 X D3 X D2 1/0 D1 1/0 D0 1/0 1/0 mode Port A mode 2 Port B mode 0-mode 0 1- mode 1 PC2 – PC0 1 – Input 0 – Output Port B 1- I/P 0-O/P Mode 2 control word PC3 PA0-PA7 INTR INTE 1 PC7 PC6 OBF ACK STB IBF 3 I/O INTE 2 RD WR PC4 PC5 Mode 2 pins How to cite Microprocessor and Interfacing, Papers

Microprocessor and Interfacing Free Essays

string(187) " the control register and all ports are set to the input mode e\) A0 and A1 \( Address pins \): These pins in conjunction with RD and WR pins control the selection of one of the 3 ports\." UNIT II- Peripherals and Interfacing PIO 8255 The parallel input-output port chip 8255 is also called as programmable peripheral input-output port. The Intel’s 8255 is designed for use with Intel’s 8-bit, 16-bit and higher capability microprocessors. It has 24 input/output lines which may be individually programmed in two groups of twelve lines each, or three groups of eight lines. We will write a custom essay sample on Microprocessor and Interfacing or any similar topic only for you Order Now The two groups of I/O pins are named as Group A and Group B. Each of these two groups contains a subgroup of eight I/O lines called as 8-bit port and another subgroup of four lines or a 4-bit port. Thus Group A contains an 8-bit port A along with a 4-bit port. C upper. PIO 8255 †¢ The port A lines are identified by symbols PA0-PA7 while the port C lines are identified as PC4-PC7. Similarly, GroupB contains an 8-bit port B, containing lines PB0-PB7 and 4-bit port C with lower bits PC0- PC3. The port C upper and port C lower can be used in combination as an 8-bitport C. †¢ Both the port C are assigned the same address. Thus one may have either three 8-bit I/O ports or two 8-bit and two 4-bit ports from 8255. All of these ports can function independently either as input or as output ports. This can be achieved by programming the bits of an internal register of 8255 called as control word register ( CWR ). PIO 8255 †¢ The internal block diagram and the pin configuration of 8255 are shown in fig. †¢ The 8-bit data bus buffer is controlled by the read/write control logic. The read/write control logic manages all of the internal and external transfers of both data and control words. †¢ RD, WR, A1, A0 and RESET are the inputs provided by the microprocessor to the READ/ WRITE control logic of 8255. The 8-bit, 3-state bidirectional buffer is used to interface the 8255 internal data bus with the external system data bus. PIO 8255 †¢ This buffer receives or transmits data upon the execution of input or output instructions by the microprocessor. The control words or status information is also transferred through the buffer. †¢ The signal description of 8255 are briefly presented as follows : †¢ PA7-PA0: These are eight port A lines that acts as either latched output or buffered input lines depending upon the control word loaded into the control word register. †¢ PC7-PC4 : Upper nibble of port C lines. They may act as either output latches or input buffers lines. PIO 8255 This port also can be used for generation of handshake lines in mode 1 or mode 2. †¢ PC3-PC0 : These are the lower port C lines, other details are the same as PC7-PC4 lines. †¢ PB0-PB7 : These are the eight port B lines which are used as latched output lines or buffered input lines in the same way as port A. †¢ RD : This is the input line driven by the microprocessor and should be low to indicate read operation to 8255. †¢ WR : This is an input line driven by the microprocessor. A low on this line indicates write operation. PIO 8255 †¢ CS : This is a chip select line. If this line goes low, it enables the 8255 to respond to RD and WR signals, otherwise RD and WR signal are neglected. †¢ A1-A0 : These are the address input lines and are driven by the microprocessor. These lines A1-A0 with RD, WR and CS from the following operations for 8255. These address lines are used for addressing any one of the four registers, i. e. three ports and a control word register as given in table below. †¢ In case of 8086 systems, if the 8255 is to be interfaced with lower order data bus, the A0 and A1 pins of 8255 are connected with A1 and A2 respectively. RD 0 0 0 0 RD 1 1 1 1 RD X 1 WR 1 1 1 1 WR 0 0 0 0 WR X 1 CS 0 0 0 0 CS 0 0 0 0 CS 1 0 A1 0 0 1 1 A1 0 0 1 1 A1 X X A0 0 1 0 1 A0 0 1 0 1 A0 X X Input (Read) cycle Port A to Data bus Port B to Data bus Port C to Data bus CWR to Data bus Output (Write) cycle Data bus to Port A Data bus to Port B Data bus to Port C Data bus to CWR Function Data bus tristated Data bus tristated Control Word Register PIO 8255. †¢ D0-D7 : These are the data bus lines those carry data or control word to/from the microprocessor. †¢ RESET : A logic high on this line clears the control word register of 8255. All ports are set as input ports by default after reset. Block Diagram of 8255 (Architecture) ( cont.. ) †¢ 1. 2. 3. 4. †¢ It has a 40 pins of 4 groups. Data bus buffer Read Write control logic Group A and Group B controls Port A, B and C Data bus buffer: This is a tristate bidirectional buffer used to interface the 8255 to system databus. Data is transmitted or received by the buffer on execution of input or output instruction by the CPU. Control word and status information are also transferred through this unit. †¢ Block Diagram of 8255 (Architecture) ( cont.. ) Read/Write control logic: This unit accepts control signals ( RD, WR ) and also inputs from address bus and issues commands to individual group of control blocks ( Group A, Group B). †¢ It has the following pins. a) CS – Chipselect : A low on this PIN enables the communication between CPU and 8255. b) RD (Read) – A low on this pin enables the CPU to read the data in the ports or the status word through data bus buffer. †¢ Block Diagram of 8255 (Architecture) ( cont.. ) WR ( Write ) : A low on this pin, the CPU can write data on to the ports or on to the control register through the data bus buffer. ) RESET: A high on this pin clears the control register and all ports are set to the input mode e) A0 and A1 ( Address pins ): These pins in conjunction with RD and WR pins control the selection of one of the 3 ports. You read "Microprocessor and Interfacing" in category "Papers" †¢ Group A and Group B controls : These block receive control from the CPU and iss ues commands to their respective ports. c) Block Diagram of 8255 (Architecture) ( cont.. ) †¢ Group A – PA and PCU ( PC7 -PC4) †¢ Group B – PCL ( PC3 – PC0) †¢ Control word register can only be written into no read operation of the CW register is allowed. a) Port A: This has an 8 bit latched/buffered O/P and 8 bit input latch. It can be programmed in 3 modes – mode 0, mode 1, mode 2. b) Port B: This has an 8 bit latched / buffered O/P and 8 bit input latch. It can be programmed in mode 0, mode1. Block Diagram of 8255 (Architecture). c) Port C : This has an 8 bit latched input buffer and 8 bit out put latched/buffer. This port can be divided into two 4 bit ports and can be used as control signals for port A and port B. it can be programmed in mode 0. Modes of Operation of 8255 (cont.. ) †¢ These are two basic modes of operation of 8255. I/O mode and Bit Set-Reset mode (BSR). †¢ In I/O mode, the 8255 ports work as programmable I/O ports, while in BSR mode only port C (PC0-PC7) can be used to set or reset its individual port bits. †¢ Under the I/O mode of operation, further there are three modes of operation of 8255, so as to support different types of applications, mode 0, mode 1 and mode 2. Modes of Operation of 8255 (cont.. ) †¢ BSR Mode: In this mode any of the 8-bits of port C can be set or reset depending on D0 of the control word. The bit to be set or reset is selected by bit select flags D3, D2 and D 1 of the CWR as given in table. I/O Modes : a) Mode 0 ( Basic I/O mode ): This mode is also called as basic input/output mode. This mode provides simple input and output capabilities using each of the three ports. Data can be simply read from and written to the input and output ports respectively, after appropriate initialisation. D3 0 0 0 0 1 1 1 1 D2 0 0 1 1 0 0 1 1 D1 0 1 0 1 0 1 0 1 Selected bit s of port C D0 D1 D2 D3 D4 D5 D6 D7 BSR Mode : CWR Format PA 8 2 5 5 PCU PCL PA6 – PA7 PC4 – PC7 PC0-PC3 PB PB0 – PB7 8 2 5 5 PA PCU PCL PB PA PC PB0 – PB7 All Output Port A and Port C acting as O/P. Port B acting as I/P Mode 0 Modes of Operation of 8255 (cont.. ) †¢ 1. The salient features of this mode are as listed below: Two 8-bit ports ( port A and port B )and two 4-bit ports (port C upper and lower ) are available. The two 4-bit ports can be combinedly used as a third 8-bit port. Any port can be used as an input or output port. Output ports are latched. Input ports are not latched. A maximum of four ports are available so that overall 16 I/O configuration are possible. All these modes can be selected by programming a register internal to 8255 known as CWR. 2. 3. 4. †¢ Modes of Operation of 8255 (cont.. †¢ The control word register has two formats. The first format is valid for I/O modes of operation, i. e. modes 0, mode 1 and mode 2 while the second format is valid for bit set/reset (BSR) mode of operation. These formats are shown in following fig. D7 1 D6 X D5 X D4 X D3 D2 D1 D0 0- Reset 0-for BSR mode Bit select flags D3, D2, D1 are from 000 to 111 for bits PC0 TO PC71- Set I/O Mode Control Word Register Format and BSR Mode Control Word Register Format PA3 PA2 PA1 PA0 RD CS GND A1 A0 PC7 PC6 PC5 PC4 PC0 PC1 PC2 PC3 PB0 PB1 PB2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 0 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 PA4 PA5 PA6 PA7 WR Reset D0 D1 D2 D3 D4 D5 D6 D7 Vcc PB7 PB6 PB5 PB4 PB3 8255A 8255A Pin Configuration = D0-D7 CS RESET 8255A A0 A1 RD PA0-PA7 PC4-PC7 PC0-PC3 PB0-PB7 Vcc WR GND Signals of 8255 3 Group A control 1 D0-D7 Data bus Buffer 8 bit int data bus 4 Group A Port A(8) PA0-PA7 Group A Port C upper(4) Group B Port C Lower(4) PC7-PC4 PC0-PC3 2 RD WR A0 A1 RESET CS Block Diagram of 8255 READ/ WRITE Control Logic Group B control PB7-PB0 Group B Port B(8) D7 D6 D5 Mode for Port A D4 PA D3 PC U D2 Mode for PB D1 PB D0 PC L Mode Set flag 1- active 0- BSR mode Group – A 1 Input PC u 0 Output 1 Input PA 0 Output 00 – mode 0 Mode 01 – mode 1 Select of PA 10 – mode 2 Group – B PCL PB Mode Select 1 Input 0 Output 1 Input 0 Output 0 mode- 0 1 mode- 1 Control Word Format of 8255 Modes of Operation of 8255 (cont.. ) b) Mode 1: ( Strobed input/output mode ) In this mode the handshaking control the input and output action of the specified port. Port C lines PC0-PC2, provide strobe or handshake lines for port B. This group which includes port B and PC0-PC2 is called as group B for Strobed data input/output. Port C lines PC3-PC5 provide strobe lines for port A. This group including port A and PC3-PC5 from group A. Thus port C is utilized for generating handshake signals. The salient features of mode 1 are listed as follows: Modes of Operation of 8255 (cont.. ) 1. 2. 3. 4. Two groups – group A and group B are available for strobed data transfer. Each group contains one 8-bit data I/O port and one 4-bit control/data port. The 8-bit data port can be either used as input and output port. The inputs and outputs both are latched. Out of 8-bit port C, PC0-PC2 are used to generate control signals for port B and PC3-PC5 are used to generate control signals for port A. he lines PC6, PC7 may be used as independent data lines. Modes of Operation of 8255 (cont.. ) †¢ The control signals for both the groups in input and output modes are explained as follows: Input control signal definitions (mode 1 ): †¢ STB( Strobe input ) – If this lines falls to logic low level, the data available at 8-bit input port is loaded into input latche s. †¢ IBF ( Input buffer full ) – If this signal rises to logic 1, it indicates that data has been loaded into latches, i. e. it works as an acknowledgement. IBF is set by a low on STB and is reset by the rising edge of RD input. Modes of Operation of 8255 (cont.. ) †¢ INTR ( Interrupt request ) – This active high output signal can be used to interrupt the CPU whenever an input device requests the service. INTR is set by a high STB pin and a high at IBF pin. INTE is an internal flag that can be controlled by the bit set/reset mode of either PC4 (INTEA) or PC2(INTEB) as shown in fig. †¢ INTR is reset by a falling edge of RD input. Thus an external input device can be request the service of the processor by putting the data on the bus and sending the strobe signal. Modes of Operation of 8255 (cont.. Output control signal definitions (mode 1) : †¢ OBF (Output buffer full ) – This status signal, whenever falls to low, indicates that CPU has written data to the specified output port. The OBF flip-flop will be set by a rising edge of WR signal and reset by a low going edge at the ACK input. †¢ ACK ( Acknowledge input ) – ACK signal acts as an acknowledgement to be given by a n output device. ACK signal, whenever low, informs the CPU that the data transferred by the CPU to the output device through the port is received by the output device. Modes of Operation of 8255 (cont.. ) †¢ INTR ( Interrupt request ) – Thus an output signal that can be used to interrupt the CPU when an output device acknowledges the data received from the CPU. INTR is set when ACK, OBF and INTE are 1. It is reset by a falling edge on WR input. The INTEA and INTEB flags are controlled by the bit set-reset mode of PC 6and PC2 respectively. 1 0 1 0 Input control signal definitions in Mode 1 1/0 X X X 1 X X X X 1 1 X D7 D6 D5 D4 D3 D2 D1 D0 1 – Input 0 – Output For PC6 – PC7 PA0 – PA7 INTEA PC4 PC5 STBA IBFA D7 D6 D5 D4 D3 D2 D1 D0 PB0 – PB7 INTEB PC 2 PC1 STBB IBFB PC3 RD PC6 – PC7 INTRA I/O PC0 INTR A Mode 1 Control Word Group A I/P RD Mode 1 Control Word Group B I/P STB IBF INTR RD DATA from Peripheral Mode 1 Strobed Input Data Transfer WR OBF INTR ACK Data OP to Port Mode 1 Strobed Data Output Output control signal definitions Mode 1 1 0 1 0 1/0 X X X 1 X X X X 1 0 X D7 D6 D5 D4 D3 D2 D1 D0 1 – Input 0 – Output For PC4 – PC5 PA0 – PA7 INTEA PC7 PC6 OBF ACKA D7 D6 D5 D4 D3 D2 D1 D0 PB0 PB7 INTEB PC PC2 1 OBFB ACKB PC3 WR PC4 – PC5 PC0 INTRA I/O INTRB Mode 1 Control Word Group A Mode 1 Control Word Group B Modes of Operation of 8255 (cont.. ) †¢ Mode 2 ( Strobed bidirectional I/O ): This mode of operation of 8255 is also called as strobed bidirectional I/O. This mode of operation provides 8255 with an additional features for communicating with a peripheral device on an 8-bit data bus. Handshaking signals are provided to maintain proper data flow and synchronization between the data transmitter and receiver. The interrupt generation and other functions are similar to mode 1. †¢ In this mode, 8255 is a bidirectional 8-bit port with handshake signals. The RD and WR signals decide whether the 8255 is going to operate as an input port or output port. Modes of Operation of 8255 (cont.. ) †¢ 1. 2. 3. 4. 5. The Salient features of Mode 2 of 8255 are listed as follows: The single 8-bit port in group A is available. The 8-bit port is bidirectional and additionally a 5-bit control port is available. Three I/O lines are available at port C. ( PC2 – PC0 ) Inputs and outputs are both latched. The 5-bit control port C (PC3-PC7) is used for generating / accepting handshake signals for the 8-bit data transfer on port A. Modes of Operation of 8255 (cont.. ) †¢ Control signal definitions in mode 2: †¢ INTR – (Interrupt request) As in mode 1, this control signal is active high and is used to interrupt the microprocessor to ask for transfer of the next data byte to/from it. This signal is used for input ( read ) as well as output ( write ) operations. †¢ Control Signals for Output operations: †¢ OBF ( Output buffer full ) – This signal, when falls to low level, indicates that the CPU has written data to port A. Modes of Operation of 8255 (cont.. ) ACK ( Acknowledge ) This control input, when falls to logic low level, acknowledges that the previous data byte is received by the destination and next byte may be sent by the processor. This signal enables the internal tristate buffers to send the next data byte on port A. †¢ INTE1 ( A flag associated with OBF ) This can be controlled by bit set/reset mode with PC6 . †¢ Control signals for input operations : †¢ STB (Strobe input ) A low on this line is used to strobe in the data into the input latches of 8255. Modes of Operation of 8255 (cont.. ) †¢ IBF ( Input buffer full ) When the data is loaded into input buffer, this ignal rises to logic ‘1’. This can be used as an acknowledge that the data has been received by the receiver. †¢ The waveforms in fig show the operation in Mode 2 for output as well as input port. †¢ Note: WR must occur before ACK and STB must be activated before RD. WR OBF INTR ACK STB IBF Data bus RD Mode 2 Bidirectional Data Transfer Data from 8085 Data towards 8255 Modes of Operation of 8255 (cont.. ) †¢ The following fig shows a schematic diagram containing an 8-bit bidirectional port, 5-bit control port and the relation of INTR with the control pins. Port B can either be set to Mode 0 or 1 with port A( Group A ) is in Mode 2. Mode 2 is not available for port B. The following fig shows the control word. †¢ The INTR goes high onl y if either IBF, INTE2, STB and RD go high or OBF, INTE1, ACK and WR go high. The port C can be read to know the status of the peripheral device, in terms of the control signals, using the normal I/O instructions. D7 1 D6 1 D5 X D4 X D3 X D2 1/0 D1 1/0 D0 1/0 1/0 mode Port A mode 2 Port B mode 0-mode 0 1- mode 1 PC2 – PC0 1 – Input 0 – Output Port B 1- I/P 0-O/P Mode 2 control word PC3 PA0-PA7 INTR INTE 1 PC7 PC6 OBF ACK STB IBF 3 I/O INTE 2 RD WR PC4 PC5 Mode 2 pins How to cite Microprocessor and Interfacing, Papers

Jamestown Settlement free essay sample

The first permanent English colony in North America was established at Jamestown, Virginia, in 1607. In order to earn quick profits for Virginia Company investors, the settlers wasted no time and immediately began hunting for gold and searching for the Northwest Passage to Asia. According to page forty-two in the American Journey textbook, â€Å"all they would find was suffering and disappointment,† which would foreshadow the years ahead. The colony would soon prove to be an immediate disaster. First of all the settlers neglected to plant crops because they were so eager to find new riches. The colonists had never really planned to grow all of their own food. Instead, their plans depended upon trade with the local Native Americans to supply them with enough food between the arrival of periodic supply ships from England. This quickly caused their food supplies to dwindle and many starved to death. The second mistake the settlers made is that the settlement was located in a swamp. We will write a custom essay sample on Jamestown Settlement or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page This soon led to diseases caused by parasites that were there and malaria caused by all the mosquitoes. So the settlers that didn’t starve usually died from disease. Initially Captain John Smith saved the colony through his leadership by imposing order and military discipline. However, certain settlers refused to follow his orders and believed their social status exempted them from manual labor. Just as bad was the failure of the colonists to work together for the common good, or indeed to work at all. The impending hardship was further compounded by the loss of Smith, who became injured in August of 1609 in a gunpowder accident, and was forced to return to England for medical attention in October 1609. This proved to be a major blow because he was most skillful in dealing with the Indians in trading for food. For years there was hardship and suffering in Jamestown, but in 1619 three important developments occurred. The company began to tranport women to become the wives of the planters and intice them to stay in the colony. The same year the first Africans arrived in Virginia and soon became indentured servants. The last major happening was the company created the first legislative body in English America. They were told to establish one equal and uniform government over all Virginia. According to the textbook, this also set a precedent for the establishment of self-government in other English colonies. The early years for Jamestown were full of disappointment, suffering, starvation, and tribulations. There was a constant battle going on with the Powhatan Confederacy and the colonists. Over time the settlers lost the Virginia Company, but eventually had a successful colony thanks to an established government and a marketable tobacco crop. .

The Parable of the Sadhu free essay sample

Bowen H. McCoy’s friend Stephen is quoted as saying, â€Å"I feel that what happened with the sadhu is a good example of the breakdown between the individual and corporate ethic. † Explain what you think Stephen meant by this statement. What is the nature of that breakdown between the individual and corporate ethic as you see it? In the article, Stephen goes on that â€Å"No one person was willing to assume ultimate responsibility for the sadhu. Each was willing to do his bit just so long as it was not too inconvenient. When it got to be a bother, everyone just passed the buck to someone else and took off. † Ask the students if they have ever seen such a situation in their lives? Have the students ever observed student-teams told by the professor for the last team out of the classroom to clean up, turn off lights and lock the door? Yet, when the last team walks out of the classroom, often the instructions are forgotten. We will write a custom essay sample on The Parable of the Sadhu or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Each team may blame other teams for not doing their part. Is it true that individuals tend to lose their responsibility in groups? Is it easier to hide in a group and spread the blame? 2. In reflecting on his discussion with Stephen about the sadhu McCoy says, â€Å"The instant decisions that executives make under pressure reveal the most about personal and corporate character. † Do you think on-the-spot decisions better reflect the character of the decision maker and organization rather than those that might be more thoroughly thought through? Why or why not? On-the-spot decisions reflect our habits and pattern of making decisions. This is why the Greeks argued that virtues must be practiced every day to become a habit. More thoroughly thought through decisions may not be any better than the on-the-spot ones, but may be analyzed to consider the alternatives and consequences. The ultimate decisions of either thought process reflect the character of the decision maker and organization. 3. McCoy equates the parameters of the decision-making process about the sadhu with that in business. He believes there is an interesting parallel to business situations. Explain what you think McCoy meant by this statement. Do you agree with him? McCoy points out that decision making in business is similar to what happened on the mountain: Decisions had to be made based upon what was seen and with outside influences on the processes. It is possible that the big picture may not be seen or considered; the depth or consequences may not be immediately recognized; the situation and policies may be misunderstood; the decision maker may not know of or utilize available resources. Businesspeople must be aware of the risks but cannot run away from all risks in making decisions. Often the true dimensions of the situation will not be comprehended by the manager or all members of the business team. Have the students consider the pros and cons of the parallel. 4. McCoy concludes that the lesson of the sadhu is that â€Å"in a complex corporate situation, the individual requires and deserves the support of the group. When people cannot find such support in their organizations, they don’t know how to act. † What support in organizations do you think McCoy is referring to? If such support is not found, what should individuals do when they have an ethical dilemma such as that in the sadhu case? If the organization does not provide the support to evaluate and resolve an ethical dilemma, then the individual must rely on his own values and decision making models. Below is McCoy’s reflection on the sadhu 15 years later. He notes that Stephen was reacting to the situation from his Christian ethic of compassion while he (McCoy) had a utilitarian response. Neither are the only right responses. Many students will want or state one right response, only. 5. What is the moral of the story of the sadhu from your perspective? McCoy summarized the moral as â€Å"When do we take a stand? † When Do We Take a Stand? By Bowen McCoy I wrote about my experiences purposely to present an ambiguous situation. I never found out if the sadhu lived or died. I can attest, though, that the sadhu lives on in his story. He lives in ethics classes I teach each year at business schools and churches. He lives in the classrooms of numerous business schools, where professors have taught the case to tens of thousands of students. He lives in several casebooks on ethics and on an educational video. And he lives in organizations such as the American Red Cross and ATT, which use his story in their ethics training. As I reflect on the sadhu now, 15 years after the fact, I first have to wonder, What actually happened on that Himalayan slope? When I first wrote about the event, I reported the experience in as much detail as I could remember, but I shaped it to the needs of a good classroom discussion. After years of reading my story, viewing it on video, and hearing others discuss it, I’m not sure I myself know what actually occurred on the mountainside that day! I’ve also heard a wide variety of responses to the story. The sadhu, for example, may not have wanted our help at all – he may have been intentionally bringing on his own death as a way to holiness. Why had he taken the dangerous way over the pass instead of the caravan route through the gorge? Hindu businesspeople have told me that in trying to assist the sadhu, we were being typically arrogant Westerners imposing our cultural values on the world. I’ve learned that each year along the pass, a few Nepali porters are left to freeze to death outside the tents of the unthinking tourists who hired them. A few years ago, a French group even left one of their own, a young French woman, to die there. The difficult pass seems to demonstrate a perverse version of Gresham’s law of currency: The bad practices of previous travelers have driven out the values that new travelers might have followed if they were at home. Perhaps that helps to explain why it was so difficult for Stephen or anyone else to establish a different approach on the spot. Our Sherpa sirdar, Pasang, was focused on his responsibility for bringing us up the mountain safe and sound. (His livelihood and status in the Sherpa ethnic group depended on our safe return. ) We were weak, our party was split, the porters were well on their way to the top with all our gear and food, and a storm would have separated us irrevocably from our logistical base. The fact was, we had no plan for dealing with the contingency of the sadhu. There was nothing we could do to unite our multicultural group in the little time we had. An ethical dilemma had come upon us unexpectedly, an element of dram that may explain why the sadhu’s story has continued to attract students. I am often asked for help in teaching the story. I usually advise keeping the details as ambiguous as possible. A true ethical dilemma requires a decision between two hard choices. In the case of the sadhu, we had to decide how much to sacrifice ourselves to take care of a stranger. And given the constraints of our trek, we had to make a group decision, not an individual one. If a large majority of students in a class ends up thinking I’m a bad person because of my decision on the mountain, the instructor may not have given the case its due. The same is true if the majority sees no problem with the choices we made. Any class’s response depends on its setting, whether it’s a business school, a church, or a corporation. I’ve found that younger students are more likely to see the issue as black-and-white, whereas older ones tend to see shade of gray. Some have seen a conflict between the different ethical approaches that we followed at the time. Stephen felt he had to do everything he could to save the sadhu’s life, in accordance with his Christian ethic of compassion. I had a utilitarian response: do the greatest good for the greatest number. Give a burst of aid to minimize the sadhu’s exposure, then continue on our way. The bsic question of the case remains, When do we take a stand? When do we allow a â€Å"sadhu† to intrude into our daily lives? Few of us can afford the time or effort to take care of every needy person we encounter. How much must we give of ourselves? And how do we prepare our organizations and institutions so they will respond appropriately in a crisis? How do we influence them if we do not agree with their points of view? We cannot quit our jobs over every ethical dilemma, but if we continually ignore our sense of values, who do we become? As a journalist asked at a recent conference on ethics, â€Å"Which ditch are we willing to die in? † For each of us, the answer is a bit different. How we act in response to that question defines better than anything else who we are, just as, in a collective sense, our acts define our institutions. In effect, the sadhu is always there, ready to remind us of the tensions between our own goals and the claims of strangers. References: McCracken, Janet, William Martin, and Bill Shaw. Virtue Ethics and the Parable of the Sadhu. Journal of Business Ethics 17.1 (1998): 25-38. Goodpaster, Kenneth E. Work, spirituality, and the moral point of view. International Journal of Value-Based Management 7.1 (1994): 49-62. Beyer, Janice M., and David Nino. Ethics and cultures in international business. Journal of Management Inquiry 8.3 (1999): 287-297. Amine, Lyn S. The need for moral champions in global marketing. European Journal of Marketing 30.5 (1996): 81-94. Smith, N. Craig, and John A. Quelch. Pharmaceutical marketing practices in the Third World. Journal of Business Research 23.1 (1991): 113-126.

Things They Carried: The Things They Rushed to Sell

Things They Carried: The Things They Rushed to SellIf you are looking for samples of what they carried, you might want to consider checking out the things they carried for the 2020 Ohio Historical Society, Columbus, Ohio. This is one of the sites available from the Ohio Memory Project.As you might imagine, some of the things they carried are very interesting. Some are very unusual, but they are well known and well documented. Here are some examples:The first yard sale (we know of) was made in Dublin, Ohio, at 123 Renfrew Road. This one brought in a number of artifacts including some buttons, beads, and glazed bowls. The family who owned the house and lived there, purchased a brass swing set and 'moved out' of the house.The second yard sale took place in Brecksville, Ohio, at the man's home, on Pointe Drive, just west of the Ohio River. The artifacts sold in this yard sale were a number of military items, including a battle flag, a scrap of a military jacket and what appeared to be an American flag.Another of the four groups that stopped by in Dublin was a group of cowboys. This group brought a lot of cowhide and many headdresses. Most of the items that the cowboys brought to the yard sale were a few, but quite a few were pulled from the local market.These cowboys were from the Miami County section of Franklin County, Ohio. Of course, we know about the other groups because they had to be added to the list of the things they carried, but here is the other one:The last group of things they carried came from our very own State of Ohio. The following is a sample essay that my students will be using as an example from their Toledo Ohio classrooms. Hopefully they will get a good idea of what they were able to find in the Columbus, Ohio area.

Impact of Perry essays

Impact of Perry essays On July 8, 1853, Commodore Matthew Perry of the United States Navy, commanding a squadron of two steamers and two sailing vessels, sailed into Tokyo harbor, carrying the message to the Japanese authorities : Agree to trade in peace, or suffer the consequences in war.(Andrew Gordon, Modern History of Japan, p49). His mission signified American interest in Japan trade. After taking over California from Mexico in the 1848, Americans wanted to become a commercial power in the Pacific. Also, with the whaling supplies exhausted in the Atlantic, Americans and British whalers had ventured into the Pacific waters and facing the competition of the British, the American wanted Japanese to sell coal to their naval fleet and allow resupply stops for the whalers in Japanese ports and to open Japan as a new market for their manufactured goods. Japan at this time was ruled by the shogun from the Tokugawa family and during this period, Japanese contacts with outsiders were severely limited, primarily due to the fear of the shogun and the other samurai that outside contacts presented a potential threat to their power. In response to this incident, the shogun ordered defence to be strengthened along the coastline and rumours of impending war sparked off panic in Japan. Also, the shogun did something unprecedented and unusual, he actually requested the various daimyos submit their advice on how to best deal with the Americans in hope of rallying a consensus for his choice to make some concessions and avoid war(Gordan, Modern History of Japan, p49). In early 1854, he returned with a fleet of 9 ships and the Japanese tried to intimidate the Americans but to no avail, and faced with the firmness of Perry and aware of their military strength relative to the Americans, the shogun signed the Treaty of Kanagawa which opened 2 ports(Shimoda and Hakodate) to the Americans. This event was followed by similar treaties with other Western p...

Politics of George Clooney, Actor and Liberal Activist

Politics of George Clooney, Actor and Liberal Activist American actor George Clooney is a liberal, a strong supporter of liberal causes and charities, and an outspoken critic of conservative politics and warmongering. Clooney supported John Kerry for President in 2004; Barack Obama in 2008 and 2012, and Hilary Clinton in 2016. Among other causes, he actively supports gay rights. Im a liberal. Im confused when that became a bad word. Its interesting. I think what happened over a period of time, probably in the late 80s when it became sort of a political tool.... [T]he liberal movement morally, you know, has stood on the right side of an awful lot of issues. We thought that blacks should be allowed to sit at the front of the bus and women should be able to vote, McCarthy was wrong, Vietnam was a mistake.  George Clooney to CNNs Larry King on February 16, 2006. Actor, Director, Producer George Clooney is best-known as having been a television and film actor since early 1980s, and as a director and film producer since 2002s Confessions of a Dangerous Mind. Most Americans first noticed him as the handsome Dr. Doug Ross on the popular television program ER from 1994 to 1999. Clooney regularly appeared in five other television shows prior to ER. Clooneys acting credits range from the goofy Return of the Killer Tomatoes (1988) to the seriocomic O Brother Where Art Thou, the Coen brothers 2000 take on Homers The Odyssey. His writing, producing, and directing credits include political-commentary films such as Syriana (2005) and The American (2010), as well as historically-themed films such as The Monuments Men (2014) and Good Night, and Good Luck (2006). The Clooney Family George Clooney was born in 1961 near Lexington, Kentucky to Nick Clooney, a regional newscaster and well-liked TV personality, and Nina Warren Clooney, local city council member, and former Kentucky beauty queen. Hes also the nephew of the singer Rosemary Clooney and cousin of actor Miguel Ferrer. One 2003 article dubs the Clooney clan the Kennedys of Kentucky for their formidable liberal influence in the conservative northern part of that state. By all reports, the Clooneys are a close-knit, Irish-Catholic family, and George is fiercely loyal to his father. When Nick Clooney ran for Congress in 2004, George raised over $600,000 from fellow celebrity-activists for his fathers unsuccessful campaign and made personal appearances on behalf of his father. Charity Causes In the charity world, Clooney is known for his work with numerous disaster relief efforts, including America: A Tribute to Heroes in 2001 for victims of 9/11; Tsunami Aid: A Concert of Hope, to benefit victims of the late-2004 Indian Ocean tsunami; and the Hope for Haiti Now for the victims of the 2010 earthquake. Clooney donated $1 million in September 2005 to the United Way Hurricane Katrina Response Fund to help out the victims of the hurricane. Clooney is a member of the United Way Board of Trustees. Said Clooney when he made the donation, Today our neighbors need food, shelter, and health care, but the very near future is when the difficult part of rebuilding lives and homes and cities starts. Were all in this one together. In March 2006, Clooney donated his Oscar gift-bag (Value: about $100,000) to the United Way, to be auctioned off to benefit that humanitarian organizations programs. Preventing Mass Atrocities Clooney has also contributed money and time to the recognition, prevention, and cessation of genocides and mass atrocities. He was instrumental in the creation of Journey to Darfur, a program on the ongoing conflict in Darfur; the recognition of the Armenian Genocide; the Satellite Sentinel Project reporting on the civil war between Sudan and South Sudan; and the Aurora Prize, which awards people who risk their lives to present genocides and atrocities. In 2006, Clooneys longtime liberal activism and unabashed political views also rose to headline-attracting public prominence. After a 5-day visit to Darfur, Clooney spoke out against genocide in that country and urged greater US and NATO involvement. In September 2006, Clooney testified before the UN Security Council, urging that UN peacekeepers enter Darfur. Clooney and the Conservative Media Clooney has been the focus of attacks from conservative media outlets. In September 2001, Clooney was a primary organizer on a telethon to raise money for victims of 9/11. The program, America: A Tribute to Heroes raised US $129 million which was donated to The United Way. Conservative political commentator Bill OReilly took Clooney and his associates to task for not appearing on The OReilly Factor program to respond to scattered news reports that the money was not, in fact, going to the victims. Infuriated, Clooney responded in an angry letter to OReilly on November 6, 2001, in which he scolded, The fund is not only the most successful single fundraiser ever, it is doing exactly what it is designed to do. Responsibly. The money is going out to the right people... In 2014, the British tabloid The Daily Mail reported that the family of his then-fiancee, Amal Alamuddin, opposed their marriage on religious grounds, saying that some of her relatives had joked about killing the bride if she disobeyed her parents. Clooney wrote an open letter in the USA Today calling the paper a laughable tabloid that crossed into the arena of inciting violence. A Few Political Films Over his career, Clooney has appeared in and had some creative control over the production of several films with political content. Here are a few of the best known. Three Kings (1999)- At the Gulf Wars end, four US soldiers come across a potential jackpot: a rolled up treasure map to Saddam Husseins stashes of confiscated gold hidden bewteen the buttocks of a captured soldier. While pursuing selfish gain, the men collide with Iraqi civilians and experience a different side of the war.Confessions of a Dangerous Mind  (2002)- Based on the life of Chuck Barris, who claimed dual careers as loony game-show host and CIA operative for the US government. Also directed by Clooney.Good Night, and Good Luck (2005)- Taking place during the early days of broadcast journalism in 1950s America, this film chronicles the real-life conflict between newsman Edward R. Murrow and Senator Joseph McCarthy and his House Un-American Activities Committee. In a political climate of fear and reprisal, the CBS news crew persists. McCarthy is brought before the Senate and made powerless as his lies and bullying tactics are finally uncovered. Clooney was nominated for a Bes t Director Oscar for this film. Syriana (2005)- In this political thriller that unfolds against the intrigue of the global oil industry, Clooney plays the role of career CIA operative who disturbing truths about the work to which he has devoted his life. He won the 2006 Best Supporting Oscar and a Golden Globe for this role.The Ides of March (2011)- Clooney directed and co-wrote the screenplay for this take on modern-day dirty politics,Money Monster (2016)- A financial TV hose and his producer are taken hostage by an irate investor who is convinced there is a conspiracy driving fluctuations in global high tech markets. Summing Up Liberalism When asked in 2005 by the German magazine Brigitte, why conservatives continually vilify liberals, Clooney succinctly summed up liberalism.... Its quite amazing that liberal nowadays has become a swear word as in the history of our country it always meant to be on the side of justice. It started with the witchhunt in Salem, the conservatives point of view was: Burn them at the stake, and the liberals point of view was: There are no witches. And thats how it continued with the civil rights movement and womens suffrage. The liberals were always right in the end. Sources: Carr. 2005. A ringside seat for Murrow versus McCarthy. The New York Times, 18 September 2005.Cieply M. 2010. Within days, a global benefit takes shape. The New York Times 21 January 2010. Gibson, C. 2017. George Clooney takes aim at powerhourse D.C. lobbying firm over its ties to the Sudanese government. The Washington Post 7 July 2017.Somaiya R and Haughney C. 2014. Heard the News on George Clooney? This Much Is True: He’s Livid. The New York Times, 11 July 2014.Internet Movie Database (IMDb). 2017 George Clooney. Downloaded 24 November 2017