What are the features used for Mode 0 in 8255?
The input/output features in mode 0 are as follows: Output ports are latched. Input ports are buffered, not latched. Ports do not have handshake or interrupt capability.
Which of the following are the features of 8255A?
Features of 8255A
- It consists of 3 8-bit IO ports i.e. PA, PB, and PC.
- Address/data bus must be externally demux’d.
- It is TTL compatible.
- It has improved DC driving capability.
What is the use of Mode 2 in 8255A PPI?
Mode 2 – Bidirectional I/O: In this mode only port A will work, port B can either is in mode 0 or 1 and port C bits are used as handshake signal. The outputs as well as inputs are latched. It has interrupt handling capability.
What are the features used Mode 1 in 8255?
The mode 1 which supports handshaking has following features:
- Two ports i.e. port A and B can be used as 8-bit I/O ports.
- Each port uses three lines of port c as handshake signal and remaining two signals can be used as I/O ports.
- Interrupt logic is supported.
- Input and Output data are latched.
Which of the following are features of 8255 Mcq?
Explanation: 8255A has three ports, i.e., PORT A, PORT B, and PORT C. 3.
What are the main features of 8255 draw and explain the control word register format of 8255?
The control word format of the 8255 is shown in Fig. below. The contents of the control register are called the control word that specifies the input/ output functions of each port. The control word register can be accessed to write the control word by selecting AD_1 and AD_0 in high condition i.e. both ON.
What is the operation for Mode 0 Mcq?
Solution: In mode 0, any port can be used as input or output and output ports are latched. Solution: In this mode, the handshaking signals control the input or output action of the specified port.
Which mode in 8254 generates a strobe in response to an software Mode 3 Mode 4 Mode 5 Mode 6?
Mode 5 – Hardware Triggered Mode This mode generates a strobe in response to an externally generated signal. This mode is similar to mode 4 except that the counting is initiated by a signal at the gate input, which means it is hardware triggered instead of software triggered.
In which mode do all the ports of the 8255 PPI?
Explanation: The 8255 ports work in the I/O mode as programmable I/O ports.
Which port of 8255 can be used in all 3 modes?
In this mode only port C bits are used for set or reset. If MSB of control word (D7) is 1, PPI works in input-output mode. This is further divided into three modes: Mode 0 –In this mode all the three ports (port A, B, C) can work as simple input function or simple output function.
Which of the following is are the control handshake signal in Mode 1 of 8255?
From the given option, OBF, IBF & STB are handshaking signals in mode-1 of 8255.
Which port is used for the generation of handshake lines in Mode 1 or Mode 2?
Port C upper
Explanation: Port C upper is used for the generation of handshake lines in mode 1 or mode 2.