Baud rate is also affected by a bit in the PCON register.
PCON.7 is SMOD bit. If SMOD = 1, baud rate will be
doubled in modes 1, 2 and 3.
Mode 2 baud rate is the 1/64
the oscillator frequency
(SMOD = 0) and can be doubled to 1/32
frequency (SMOD = 1).
PCON is not bit-addressable, setting SMOD without
altering the other bits requires a “
operation as follows:
MOV A, PCON
; Get current value of PCON
; Set SMOD
MOV PCON, A
; Write value back to PCON