IS80LV51 Datasheet, PDF (13/43 Pages) Integrated Silicon Solution, Inc – CMOS SINGLE CHIP LOW VOLTAGE 8-BIT MICROCONTROLLER

IS80LV51
IS80LV31
ISSI ^®
TMOD:
Timer/Counter Mode Control Register.
Not Bit Addressable.
Timer 1
GATE C/T M1 M0
Timer 0
GATE C/T M1 M0
GATE When TRx (in TCON) is set and GATE=1, TIMER/
COUNTERx will run only while INTx pin is high
(hardware control). When GATE=0, TIMER/
COUNTERx will run only while TRx=1 (software
control).
C/T Timer or Counter selector. Cleared for Timer
operation (input from internal system clock). Set
for Counter operation (input from Tx input pin).
M1 Mode selector bit.⁽¹⁾
M0 Mode selector bit.⁽¹⁾
Note 1:
M1 M0 Operating mode
0 0 Mode 0. (13-bit Timer)
0 1 Mode 1. (16-bit Timer/Counter)
1 0 Mode 2. (8-bit auto-load Timer/
Counter)
1 1 Mode 3. (Splits Timer 0 into TL0 and
TH0. TL0 is an 8-bit Timer/Counter
controller by the standard Timer 0
control bits. TH0 is an 8-bit Timer and
is controlled by Timer 1 control bits.)
1 1 Mode 3. (Timer/Counter 1 stopped).
SCON:
Serial Port Control Register. Bit Addressable.
7
65
4
3
2
10
SM0 SM1 SM2 REN TB8 RB8 TI RI
Register Description:
SM0 SCON.7 Serial port mode specifier.⁽¹⁾
SM1 SCON.6 Serial port mode specifier.⁽¹⁾
SM2
SCON.5
Enable the multiprocessor com-
munication feature in mode 2 and 3. In
mode 2 or 3, if SM2 is set to 1 then RI
will not be activated if the received 9th
data bit (RB8) is 0. In mode 1, if
SM2=1 then RI will not be activated if
valid stop bit was not received. In
mode 0, SM2 should be 0.
REN SCON.4 Set/Cleared by software to Enable/
Disable reception.
TB8 SCON.3 The 9th bit that will be transmitted in
mode 2 and 3. Set/Cleared by
software.
RB8 SCON.2 In modes 2 and 3, RB8 is the 9th data
bit that was received. In mode 1, if
SM2=0, RB8 is the stop bit that was
received. In mode 0, RB8 is not used.
TI SCON.1 Transmit interrupt flag. Set by
hardware at the end of the 8th bit time
in mode 0, or at the beginning of the
stop bit in the other modes. Must be
cleared by software.
RI SCON.0 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 (except see SM2).
Must be cleared by software.
Note:
SM0 SM1 MODE Description
0 0 0 Shift register
0
1
1
8-bit UART
1
0
2
9-bit UART
1
1
3
9-bit UART
Baud rate
Fosc/12
Variable
Fosc/64 or
Fosc/32
Variable
Integrated Silicon Solution, Inc.
13
ADVANCE INFORMATION MC018-0A
10/01/98