7480 Datasheet, PDF (31/98 Pages) Bi technologies – 7/8 Diameter 5-Turn Wirewound Precision Potentiometer

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MITSUBISHI MICROCOMPUTERS
7480/7481 GROUP
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
q Timers 1 and 2
Timer 1 and timer 2 are the 8-bit timers. They can select the fol-
lowing 2 modes by setting timer 1 mode register and timer 2 mode
register.
• Timer mode
• Programmable waveform generation mode
When the count source is changed, set it again as the timer value
may go wrong.
(1) Timer Mode
The frequency of f(XIN)/8, f(XIN)/64, f(XIN)/128 or f(XIN)/256 is
counted.
(2) Programmable Waveform Generation Mode
This operation is the same as the timer mode, except that a timer
outputs the level of the value set in the output level latch of the
timer 1 mode register/timer 2 mode register from the T0 or T1 pin
each time a timer underflows.
After the timer underflows, the timer can output an optional wave-
form from the T0 or T1 pin if the values of the output level latch and
timer latch are changed.
In this mode, set the port in common with the T0/T1 pin as an out-
put port.
f(XIN)/8
f(XIN)/64
f(XIN)/128
f(XIN)/256
Data bus
8
Timer count source
TL
selection bits
“00”
Count stop
8
“01”
control bit
“10”
T
“11”
Timer interrupt
request bit
T0, T1 output
T
QD
Output
level latch
Fig. 26 Block diagram of timer 1, timer 2
Data bus
8
Timer mode register
8
b7
b0
Timer 1 mode register (T1M : address 00F916)
Timer 2 mode register (T2M : address 00FA 16)
Timer stop control bit
0 : Count operation
1 : Count stop
Timer operation mode bit
0 : Timer mode
1 : Programmable waveform generation mode
Not used (“0” at read)
Output level latch
0 : “L” output
1 : “H” output
Not used (“0” at read)
Timer count source selection bits
b7 b6
0 0 : f(XIN)/8
0 1 : f(XIN)/64
1 0 : f(XIN)/128
1 1 : f(XIN)/256
Fig. 27 Structure of timer 1/timer 2 mode register
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