Question

The register of 8257 that can only be written in is

(a) DMA address register

(b) Terminal count register

(c) Mode set register

(d) Status register

The question was asked in final exam.

I'd like to ask this question from DMA Transfers and Operations in portion DMA, Floppy Disk and CRT Controllers of Microprocessor

Answer 1

Correct option is (c) Mode set register

The explanation is: The selected register may be read or written depending on the instruction executed by the CPU. But only write operation can be performed on the mode set register.