IS80C51 Datasheet, PDF (23/43 Pages) Integrated Silicon Solution, Inc – CMOS SINGLE CHIP 8-BIT MICROCONTROLLER

IS80C51
IS80C31
ISSI ^®
IS80C51/31 INTERNAL BUS
TB8
WRITE
TO
SBUF
DSQ
CL
SBUF
PHASE 2 CLOCK
(1/2 fOSC)
MODE 2
÷ 16
SMOD 1
÷2
SMOD 0
(SMOD IS PCON. 7)
SAMPLE
1-TO-0
TRANSITION
DETECTOR
RXD
ZERO DETECTOR
START ^{STOP BIT GEN SHIFT} DATA
TX CONTROL
TX CLOCK
TI
SEND
SERIAL
PORT
INTERRUPT
÷ 16
RX RI
START ^CLOCK
RX CONTROL
LOAD
SBUF
SHIFT
1FFH
BIT
DETECTOR
INPUT SHIFT REG.
(9 BITS)
LOAD
SBUF
SHIFT
TXD
READ
SBUF
SBUF
TX
CLOCK
IS80C51/31 INTERNAL BUS
WRITE TO SBUF
DATA
SHIFT
TXD
TI
SEND
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 14. Serial Port Mode 2
Integrated Silicon Solution, Inc. — 1-800-379-4774
23
MC003-1D
11/19/98