What are the basic modes of operation of 8255?
There are two basic modes of operation of 8255, viz.
1. I/O mode.
3. BSR mode.
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 IO mode of operation, further there are three modes of operation of 8
255, So as to support dissimilar types of applications, viz. mode 0, mode 1 and mode 2.
Mode 0 - Basic I/O mode
Mode 1 - Strobed I/O mode
Mode 2 - Strobed bi-directional I/O