Manual

High-Speed Microcontroller User’s Guide
Rev: 062210 144 of 176
Figure 12-1. Serial Port Mode 0
DIVIDE
BY 12
D7
D6
D5
D4
D3
D2
D1
D0
LOAD
CLOCK
OUTPUT SHIFT REGISTER
S0
P3.0
LATCH
RXD
PIN
RECEIVE DATA BUFFER
WRRD
D7
D6
D5
D4
D3
D2
D1
D0
CLOCK
RECEIVE SHIFT REGISTER
SI
READ
SERIAL
BUFFER
BAUD
CLOCK
LOAD
SERIAL
BUFFER
RECEIVE
BUFFER
LOAD
DATA
CLOCK
INTS
SERIAL I/O
CONTROL
SHIFT
R1
FLAG =
SCONx.0
T1
FLAG =
SCONx.1
SERIAL
INTERRUPT
DIVIDE
BY 4
LDSBUF
RDSBUF
TRANSMIT TIMING
LDSBUF
SHIFT
WRITE TO SBUF
RXD
(DATA OUT)
D0 D1 D2 D3 D4 D5 D6 D7
TXD
(DATA CLOCK)
TI
RECEIVE TIMING
RDSBUF
SHIFT
WRITE TO SCON
(
CLEAR RI
)
RXD
(DATA IN)
TXD
(DATA CLOCK)
RI
D0 D1 D2 D3 D4 D5 D6 D7
SBUF
OSC
0 1
DATA BUS
SM2=
SCONx.5
TXD
PIN