80CL31 Datasheet, PDF (18/40 Pages) NXP Semiconductors – Low-voltage single-chip 8-bit microcontrollers

Philips Semiconductors
Low-voltage single-chip 8-bit microcontrollers
Product specification
80CL31/80CL51
Timer 1
Overflow
80CL51 Internal Bus
TB8
Write
÷2
to
SMOD = 0
SMOD = 1
SBUF
DS Q
CL
S0 BUFFER
TxD
Zero Detector
÷ 16
Serial
Port
Interrupt
Sample
1-to-0
Transition
Detector
RxD
Start
TX Clock
Shift
TX Control
T1
Data
Send
÷ 16
RX Clock R1
Start
RX Control
Load
SBUF
Shift
Bit Detector
Load
SBUF
Input Shift Register
(9 Bits)
Shift
S0 BUFFER
Read
SBUF
TX
Clock
80CL51 Internal Bus
Write to SBUF
Data
Shift
TxD
Send
T
r
S1P1
a
n
s
m
i
Start Bit
D0
D1
D2
D3
D4
D5
D6
D7
TB8
Stop Bit
t
TI
Stop Bit Gen.
RX
Clock
÷ 16 Reset
R
RxD
e
Bit Detector
c
Sample Times
e
i
Shift
v
e
RI
Start
Bit
D0
D1
D2
D3
D4
D5
D6
D7
RB8
Figure 10. Serial Port Mode 3
Stop Bit
January 1995
18