Briefly Explain The 8279 Operation ?

1.	Briefly Explain The 8279 Operation ?
Answer» The 8279 is basically a programmable keyboard and a component for DISPLAY interfacing. The 8279 can scan and also ENCODE a 64 key keyboard as well as a NUMERICAL display of 16 digits. The keyboard has a buffer based on FIFO to store up to 8 keys after which the processor must retrieve a character. It contains 8 lines that can be used to connect to 8 columns of a keyboard. There are two additional lines for STB keys. Once a key is pressed they are automatically debounced and it can FUNCTION using two modes -key lockout and n-key roller. On simultaneous presses only the first key is detected. In case of n-key rollover mode all simultaneous presses are detected and stored in the internal buffer.

Answer»

The 8279 is basically a programmable keyboard and a component for DISPLAY interfacing.
The 8279 can scan and also ENCODE a 64 key keyboard as well as a NUMERICAL display of 16 digits.
The keyboard has a buffer based on FIFO to store up to 8 keys after which the processor must retrieve a character.
It contains 8 lines that can be used to connect to 8 columns of a keyboard. There are two additional lines for STB keys.
Once a key is pressed they are automatically debounced and it can FUNCTION using two modes -key lockout and n-key roller.
On simultaneous presses only the first key is detected. In case of n-key rollover mode all simultaneous presses are detected and stored in the internal buffer.

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