
Philips Semiconductors
Product data
P87LPC767
Low power, low price, low pin count (20 pin)
microcontroller with 4-kbyte OTP and 8-bit A/D converter
2002 Mar 25
43
BIT
DETECTOR
SU01181
TRANSMIT
START
BIT
STOP BIT
TX CLOCK
WRITE TO SBUF
SEND
DATA
SHIFT
TxD
TI
D0
D1
D5
D2
D6
D3
D4
D7
RECEIVE
RX CLOCK
SHIFT
RI
BIT DETECTOR SAMPLE TIMES
START
BIT
STOP BIT
RxD
D0
D1
D5
D2
D6
D3
D4
D7
÷ 16 RESET
TB8
STOP BIT GEN.
RB8
80C51 INTERNAL BUS
WRITE TO SBUF
SBUF
ZERO DETECTOR
TxD
P1.0 ALT
OUTPUT
FUNCTION
TX CONTROL
S
TX CLOCK
START
Q
CL
D
SERIAL PORT INTERRUPT
SHIFT
SEND
LOAD
SBUF
TI
INPUT SHIFT REGISTER
START
RI
LOAD SBUF
SHIFT
RX
CLOCK
1FFH
RX CONTROL
SBUF
READ
SBUF
RxD
P1.1 ALT
INPUT
FUNCTION
80C51 INTERNAL BUS
DATA
TB8
÷16
÷2
TIMER 1
OVERFLOW
SMOD1 = 0
SMOD1
= 1
1-TO-0
TRANSITION
DETECTOR
Figure 34. Serial Port Mode 3