MC80F0704/0708/0804/0808
13. TIMER/EVENT COUNTER
The MC80F0704/0708/0804/0808 has Four Timer/Counter reg-
isters. Each module can generate an interrupt to indicate that an
event has occurred (i.e. timer match).
Timer 0 and Timer 1 are can be used either two 8-bit Timer/
Counter or one 16-bit Timer/Counter with combine them. Also
Timer 2 and Timer 3 are same. Timer 4 is 16-bit Timer/Counter.
In the “timer” function, the register is increased every internal
clock input. Thus, one can think of it as counting internal 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 os-
cillator frequency.
In the “counter” function, the register is increased in response to
a 0-to-1 (rising edge) transition at its corresponding external input
pin, EC0 or EC1.
In addition the “capture” function, the register is increased in re-
sponse external or internal clock sources same with timer or
counter function. When external clock edge input, the count reg-
ister is captured into Timer data register correspondingly. When
external clock edge input, the count register is captured into cap-
ture data register CDRx.
Timer 0 and Timer 1 is shared with "PWM" function and "Com-
pare output" function. It has six operating modes: "8-bit timer/
counter", "16-bit timer/counter", "8-bit capture", "16-bit cap-
ture", "8-bit compare output", and "10-bit PWM" which are se-
lected by bit in Timer mode register TM0 and TM1 as shown in
Table 13-1, Figure 13-1 .
Timer 2 and Timer 3 is shared with "PWM" function and "Com-
pare output" function. It has six operating modes: "8-bit timer/
counter", "16-bit timer/counter", "8-bit capture", "16-bit cap-
ture", "8-bit compare output", and "10-bit PWM" which are se-
lected by bit in Timer mode register TM2 and TM3 as shown in
Table 13-2, Figure 13-2 .
16BIT
0
0
0
0
1
1
1
CAP0
0
0
1
X
0
0
1
CAP1 PWM1E
0
0
1
0
0
0
0
1
0
0
0
0
1
0
T0CK
[2:0]
XXX
111
XXX
XXX
XXX
111
XXX
T1CK
[1:0]
XX
XX
XX
XX
11
11
11
PWM1O
TIMER 0
TIMER 1
0
8-bit Timer
8-bit Timer
0
8-bit Event counter
8-bit Capture
1
8-bit Capture (internal clock) 8-bit Compare Output
1
8-bit Timer/Counter
10-bit PWM
0
16-bit Timer
0
16-bit Event counter
0
16-bit Capture (internal clock)
Table 13-1 Operation Modes of Timer 0, 1
1. X means the value of “0” or “1” corresponds to user operation.
16BIT
CAP2
CAP3 PWM3E
T2CK
[2:0]
0
0
0
0
XXX
0
0
1
0
111
0
1
0
0
XXX
0
X
0
1
XXX
1
0
0
0
XXX
1
0
0
0
111
1
1
1
0
XXX
T3CK
[1:0]
XX
XX
XX
XX
11
11
11
PWM3O
TIMER 2
TIMER 3
0
8-bit Timer
8-bit Timer
0
8-bit Event counter
8-bit Capture
1
8-bit Capture (internal clock) 8-bit Compare Output
1
8-bit Timer/Counter
10-bit PWM
0
16-bit Timer
0
16-bit Event counter
0
16-bit Capture (internal clock)
Table 13-2 Operating Modes of Timer 2, 3
50
October 31, 2011 Ver 1.03