Dear All,

Very good Afternoon,

I know this is being discussed many times about P89C51RD2.
But after having a search I could not get the solution of my problem,

The problem states like: -

I have a program which is presently working on AT89C55WD.

When I tried to program the same on P89V51RD2 the serial is not responding as expected

I have taken care of SFR at location 8E

For P89V51RD2
MOV 8E,03H

& for AT89C55WD
MOV 8E,08H

Now when I send the command for

Poll current pump status: - Command no 21

0230303038 3430 3231 030C - pump id 40 –transmit
the responce is
02 30303136 3430 3231 3032 3030 3030 3030 03 01
Pump ID Poll Command IDLE status ...
stating that the pump having address as 40 is in IDLE state

But when I try the same with P89V51RD2
I get
02 when I transmit the command for first time
30303136343032313032 when I retransmit the command &
3030303030300301 when I transmit the command for third time, sometimes this thired responce is with some FFs

The baud rate calculations for 12 clk mode for 55WD & RD2 are

RCAP2H,RCAP2L == 0xFFED
with the crystal of 12MHz

I could not get what is happining,

After going through datasheet once again I tried programming
8E as 02 for P89V51RD2 to keep
ALE is emitted at a constant rate of 1/6 the oscillator frequency

but still I got simillar responce


Please let me know what is happening



Thanks,
Sachin