stopwatch in LCD using AT89C2051

[yukato]

lcd + at89c2051

i'm working on a stopwatch using AT89C2051 and in assembly language.

i want my stopwatch to generate 1/100 of a second interrupt, such that it will display on the LCD the [second].[millisecond]... for example, 3.99

also, i am using a 12Mhz crystal and a 2x16 LCD (4-bit mode).

please help and guide me go through the process in making this project.

thank you very much.

 

[herlambang]

at89c2051 lcd

if you need 1/100 second, you should set the interrupt at 10ms.

if use 12MHz X-tall,
it's done by load the value in tlx and thx by -10000

every each interrupt reload the value:

mov thx,# high (-10000)
mov tlx,#low (-10000)

and interrupt will taken at 10000 machine cycles
one machine cycle same as X-tall/12 (1us)
1uS*10000 = 10ms

thats it. (^_^)"