I don't think you are sending a full start bit. (I haven't worked
with any 8051 in a long time, so I'm not even looking at the
hardware specifics.)
This is my crack at rewriting the ISR. Instead of using 'rotate'
to rotate the st_char an increasing number of bits each time, just
keep a partially
hi,
I am trying to implement a second UART on 89C52 by looking at atmel
application note no. ANM 055.
On a simulator I see the P3.4 (corresponding to TxD) changing properly but
nothing gets received by a computer. The connections are fine. I am
appending the code below wherein character 'A' is int
