I'm trying to implement a routine to change the serial baud rate, but whenever I try to run it, the MCU hangs and needs a hard reset. The program works fine on a simulator.
The routine is supposed to load a value from a table into RCAP2L based on the index stored in A (=0..9). RCAP2H = FFh.
All the table values and corresponding baud rates are already verified
as correct, and it's not a watchdog reset issue.
MCU = Philips P80CL580
Clock = 3.6864 MHz
Baud rate generator = Timer2
Following is the code segment:
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CLR TR2
;stop timer2 to write RCAP2L
MOV DPTR,#D_BAUDRATE
MOVC A,@A+DPTR
MOV RCAP2L,A
SETB TR2 ;restart timer2
MOV V_BUFF,#S_OK
;== delay 100ms before return to allow time for the host to change its baud rate
MOV R5,#100
FRC_BAUDDLY:
MOV R4,#154
DJNZ R4,$ ;308 cycles = 1 ms
DJNZ R5,FRC_BAUDDLY
RET

D_BAUDRATE:
DB 0A0h ; 1200bps x=0
...more table entries
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