IS89C51 Datasheet, PDF (26/48 Pages) Integrated Silicon Solution, Inc – CMOS SINGLE CHIP 8-BIT MICROCONTROLLER with 4-Kbytes of FLASH

IS89C51
ISSI ^®
TIMER 1
OVERFLOW
TIMER 2
OVERFLOW
÷2
SMOD
=0
SMOD
=1
WRITE
TO
SBUF
"0"
"1"
TCLK
÷ 16
"0"
"1"
RCLK
SAMPLE
1-TO-0
TRANSITION
DETECTOR
RXD
IS89C51 INTERNAL BUS
TB8
DSQ
CL
SBUF
ZERO DETECTOR
START
SHIFT _DATA
TX CONTROL
TX CLOCK
TI
SEND
SERIAL
PORT
INTERRUPT
÷ 16
RX CLOCK RI
START RX CONTROL
LOAD
SBUF
SHIFT
1FFH
BIT
DETECTOR
INPUT SHIFT REG.
(9 BITS)
LOAD
SBUF
SHIFT
TXD
READ
SBUF
SBUF
TX
CLOCK
IS89C51 INTERNAL BUS
WRITE TO SBUF
SEND
DATA
SHIFT
TXD
TI
S1P1
START
BIT
D0
D1
D2
D3
D4
D5
D6
D7
TB8
STOP BIT
STOP BIT GEN
TRANSMIT
RX
CLOCK
÷ 16 RESET
RXD
START
BIT D0
D1
D2
D3
D4
D5
D6
D7
RB8 STOP
BIT
RECEIVE ^{BIT DETECTOR SAMPLE TIMES}
SHIFT
RI
Figure 15. Serial Port Mode 3
26
1-800-379-4774 — Integrated Silicon Solution, Inc.
MC016-1C
11/21/98