Question

In 8251A, the pin that controls the rate at which the character is to be transmitted is

(a) TXC(active low)

(b) TXC(active high)

(c) TXD(active low)

(d) RXC(active low)

This question was addressed to me in a national level competition.

My enquiry is from Programmable Communication Interface 8251 USART in section Special Purpose Programmable Peripheral devices and their Interfacing of Microprocessor

Answer 1

Correct option is (a) TXC(active low)

The explanation is: Transmitter Clock Input (TXC(active low)) is a pin that controls the rate at which the character is to be transmitted.