GMS81C1102 Datasheet, PDF (47/89 Pages) Hynix Semiconductor – 8-BIT SINGLE-CHIP MICROCONTROLLERS

GMS81C1102 / GMS81C1202
16. TIMER / COUNTER
The GMS81C1202 has two Timer/Counter registers. Each
module can generate an interrupt to indicate that an event
has occurred (i.e. timer match).
Timer 0 and Timer 1 can be used either the two 8-bit Tim-
er/Counter or one 16-bit Timer/Counter by combining
them.
In the "timer" function, the register is increased every in-
ternal clock input. Thus, one can think of it as counting in-
ternal clock input. Since a least clock consists of 2 and
most clock consists of 2048 oscillator periods, the count
rate is 1/2 to 1/2048 of the oscillator frequency in Timer0.
And Timer1 can use the same clock source too. In addition,
Timer1 has more fast clock source ( 1/1 to 1/8 ).
In the "counter" function, the register is increased in re-
sponse to a 0-to-1 (rising edge) transition at its correspond-
ing external input pin, EC0.
And in the "capture" function, the register is increased in
response external interrupt same with timer function.
When external interrupt edge input, the count register is
captured into capture data register CDRx.
Timer1 is shared with "PWM" function and "Compare out-
put" function
It has seven operating modes: "8-bit timer/counter", "16-
bit timer/counter", "8-bit capture", "16-bit capture", "8-bit
compare output", "16-bit compare output" and "10-bit
PWM" which are selected by bit in Timer mode register
TM0 and TM1 as shown in Figure 16-1 and Table 16-1.
Timer 0 Mode Register
TM0
-
-
CAP0 T0CK2 T0CK1 T0CK0 T0CN T0ST
ADDRESS : D0H
RESET VALUE : --000000
CAP0
T0CK[2:0]
Capture mode selection bit.
0 : Disables Capture
1 : Enables Capture
T0CN
Input clock selection
000 : fxin ÷ 2
001 : fxin ÷ 4
010 : fxin ÷ 8
011 : fxin ÷ 32
100 : fxin ÷ 128
101 : fxin ÷ 512
110 : fxin ÷ 2048
111 : External Event ( EC0 )
T0ST
Timer 1 Mode Register
TM1
POL
16BIT PWME CAP1 T1CK1 T1CK0
Continue control bit
0 : Stop counting
1 : Start counting continuously
Start control bit
0 : Stop counting
1 : Start countingn
T1CN T1ST
ADDRESS : D2H
RESET VALUE : 00000000
POL
16BIT
PWME
CAP1
PWM Output Polarity
0 : Duty active low
1 : Duty active high
16-bit mode selection
0 : 8-bit mode
1 : 16-bit mode
PWM enable bit
0 : Disables PWM
1 : Enables PWM
Capture mode selection bit.
0 : Disables Capture
1 : Enables Capture
T1CK[2:0]
T1CN
T1ST
Input clock selection
00 : fxin
10 : fxin ÷ 8
01 : fxin ÷ 2
11 : using the Timer 0 clock
Continue control bit
0 : Stop counting
1 : Start counting continuously
Start control bit
0 : Stop counting
1 : Start countingn
Figure 16-1 Timer 0 and Timer 1 Mode Register
44
Jan. 2002 ver 2.0