W77L32 Datasheet, PDF (62/76 Pages) Winbond – 8-BIT MICROCONTROLLER

W77L32/W77L032A/W77M032A
which the SBUF and RB8 are loaded and RI is set. However certain conditions must be met before the
loading and setting of RI can be done.
1. RI must be 0 and
2. Either SM2 = 0, or the received stop bit = 1.
If these conditions are met, then the stop bit goes to RB8, the 8 data bits go into SBUF and RI is set.
Otherwise the received frame may be lost. After the middle of the stop bit, the receiver goes back to
looking for a 1-to-0 transition on the RxD pin.
Clock Source
Mode input
div. by 4 osc/2
div. by 64 osc/32
div. by 1024 osc/512
÷2≅6Χ
Write to
SBUF
TB8
Internal
Data Bus
SMOD= _{0 1}
(SMOD_1)
÷16
÷16
SAMPLE
1-TO-0
DETECTOR
TX START
TX CLOCK
TX
SHIFT
TI
SERIAL
CONTROLLER _RI
RX CLOCK
RX START
LOAD
SBUF
RX SHIFT
RXD
BIT
DETECTOR
D8
STOP
PARIN
START SOUT
LOAD
T
CLOCK
Transmit Shift Register
TXD
Serial Port
Interrupt
CLOCK
PAROUT
SIN
D8
SBUF
RB8
Receive Shift Register
Read
SBUF
Internal
Data
Bus
Figure 22. Serial Port Mode 2
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