8254定时器的频率

Frequency of 8254 Timer

我是汇编语言的新手。我想知道定时器芯片8254的实际频率是多少

我上网查了很多不同的答案,比如最大频率是 8 MHz、1.1 MHz 等等,

 Which one is right?

8253和8254时序芯片上的Wikipedia page好像暗示你问题的答案是1.1MHz:

The timer that is used by the system on x86 PCs is Channel 0, and its clock ticks at a theoretical value of 1193181.8181... Hz, i.e. one third of the NTSC color subcarrier frequency, which comes from dividing the system clock (14.31818 MHz) by 12.

维基百科页面暗示该芯片的频率是 NTSC 彩色副载波频率 3.6 MHz 的倍数。我可以反对 8 MHz 作为定时频率,因为它 不是 8 MHz 的倍数 (8 / 3.6 = 2.2)。