Oki MSM80C154S, Specification Sheet, Page: 11 / 36

269
MSM80C154S/83C154S ¡ Semiconductor
Timer/counter 0 mode setting
NAME ADDRESS
MSB LSB
7 6 5 4 3 2 1 0
BIT LOCATION FLAG FUNCTION
TMOD 89H GATE C/
T
M1 M0 GATE C/
T
M1 M0
TMOD.0 M0 M1 M0
8-bit timer/counter with 5-bit prescalar. 0 0
16-bit timer/counter. 0 1
8-bit timer/counter with 8-bit auto reloading. 1 0
Timer/counter 0 separated into TLO (8-bit) timer/counter
and TH0 (8-bit) timer/counter. TF0 is set by TL0 carry, and
TF1 is set by TH0 carry. 1 1 TMOD.1 M1
Timer/counter 0 count clock designation control bit.
XTAL1•2 divided by 12 clocks is the input applied to timer/counter 0 when
C/
T
= "0".
The external clock applied to the T0 pin is the input applied to timer/counter 0
when C/
T
= "1".
TMOD.2 C/
T
When this bit is "0", the TR0 bit of TCON (timer control register) is used to
control the start and stop of timer/counter 0 counting.
If this bit is "1", timer/counter 0 starts counting when both the TR0 bit of TCON
and
INT0
pin input signal are "1", and stops counting when either is changed
to "0".
TMOD.3 GATE
Timer/counter 1 mode setting TMOD.4 M0 M1 M0
8-bit timer/counter with 5-bit prescalar. 0 0
16-bit timer/counter 0 1
8-bit timer/counter with 8-bit auto reloading. 1 0
Timer/counter 1 operation stopped. 1 1
TMOD.5 M1
Timer/counter 1 count clock designation control bit.
XTAL1•2 divided by 12 clocks is the input applied to timer/counter 1 when
C/
T
= "0".
The external clock applied to the T1 pin is the input applied to timer/counter 1
when C/
T
= "1".
TMOD.6 C/
T
When this bit is "0", the TR1 bit of TCON is used to control the start and stop of
timer/counter 1 counting.
If this bit is "1", timer/counter 1 starts counting when both the TR1 bit of TCON
and
INT1
pin input signal are "1", and stops counting when either is changed
to "0".
TMOD.7 GATE
Special Function Registers
Timer mode register (TMOD)