80CL31 Datasheet, PDF (13/40 Pages) NXP Semiconductors – Low-voltage single-chip 8-bit microcontrollers

Philips Semiconductors
Low-voltage single-chip 8-bit microcontrollers
Product specification
80CL31/80CL51
MSB
LSB
SM0 SM1 SM2 REN TB8 RB8 T1 R1
Where SM0, SM1 specify the serial port mode, as follows:
SM0
0
0
1
1
SM1
0
1
0
Mode
0
1
2
1
3
Description
Baud Rate
shift register
8-bit UART
f_OSC/ 12
variable
9-bit UART
f_OSC/64
or
f_OSC/32
9-bit variable UART
SM2
REN
TB8
RB8
TI
RI
Enables the multiprocessor communication feature in Modes 2 and 3. In Mode 2 or 3, if SM2 is set to 1 then Rl will not
be activated if the received 9th data bit (RB8) is 0. In Mode 1, if SM2=1 then R1 will not be activated if a valid stopbit
was not received. In Mode 0, SM2 should be 0.
Enables serial reception. Set by software to enable reception. Clear by software to disable reception.
Is the 9th data bit that will be transmitted in Modes 2 and 3. Set or clear by software as desired.
In Modes 2 and 3, is the 9th data bit that was received. In Mode 1, it SM2=0, RB8 is the stop bit that was received. In
Mode 0, RB8 is not used.
Is transmit interrupt flag. Set by hardware at the end of the 8th time in Mode 0, or at the beginning of the stop bit in the
other modes, in any serial transmission. Must be cleared by software.
Receive interrupt flag. Set by hardware at the end of the 8th bit time in Mode 0, or halfway through the stop bit time in
the other modes, in any serial reception except (see SM2). Must be cleared by software.
Figure 6. Serial Port control (SCON) Register
Table 2. Timer 1 Generated Commonly Used Baud Rates
BAUD RATE
f_OSC
SMOD
C/T
Mode 0 Max: 1.33 Mb/s
16 MHz
x
x
Mode 2 Max: 500 Kb/s
16 MHz
1
x
Modes 1,3: 83.3 Kb/s
16 MHz
1
0
19.2 Kb/s
11.059 MHz
1
0
9.6 Kb/s
11.059 MHz
0
0
4.8 Kb/s
11.059 MHz
0
0
2.4 Kb/s
11.059 MHz
0
0
1.2 Kb/s
11.059 MHz
0
0
137.5 Kb/s
11.986 MHz
0
0
110
6 MHz
0
0
110
12 MHz
0
0
TIMER 1
MODE
RELOAD VALUE
x
x
x
x
2
FFH
2
FDH
2
FDH
2
FAH
2
F4H
2
E8H
2
1DH
2
72H
1
FEEBH
January 1995
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