IC80C51
IC80C31
IC80C51/31 INTERNAL BUS
TB8
TIMER 1
OVERFLOW
WRITE
TO
SBUF
S
2
Q
D
SBUF
SMOD
= 1
TXD
CL
SMOD
= 0
ZERO DETECTOR
SHIFT
TX CONTROL
START
DATA
RX CLOCK
SEND
16
TI
SERIAL
PORT
INTERRUPT
16
SAMPLE
1-TO-0
LOAD
RI
RX CLOCK
START
SBUF
SHIFT
1FFH
RX CONTROL
TRANSITION
DETECTOR
BIT
DETECTOR
INPUT SHIFT REG.
(9 BITS)
RXD
LOAD
SBUF
SHIFT
SBUF
READ
SBUF
IC80C51/31 INTERNAL BUS
TX CLOCK
WRITE TO SBUF
SEND
S1P1
TRANSMIT
DATA
SHIFT
START
BIT
D0
D1
D2
D3
D4
D5
D6
D7
STOP BIT
TXD
TI
RX
CLOCK
16 RESET
START
BIT
RXD
D0
D1
D2
D3
D4
D5
D6
D7
STOP BIT
BIT DETECTOR SAMPLE TIMES
RECEIVE
SHIFT
RI
Figure 12. Serial Port Mode 1
Integrated Circuit Solution Inc.
MC001-0B
23
ICSI [ INTEGRATED CIRCUIT SOLUTION INC ]
