µPD75216A
5.6 TIMER/PULSE GENERATOR
The µPD75216A incorporates one channel of timer/pulse generator which can be used as a timer or a pulse
generator. The timer/pulse generator has the following functions.
(a) Functions available in the timer mode
• 8-bit interval timer operation (IRQTPG generation) enabling the clock source to be varied at 5 levels
• Square wave output to PPO pin
(b) Functions available in the PWM pulse generation mode
• 14-bit accuracy PWM pulse output to the PPO pin (Used as a digital-to-analog converter and applicable
to tuning)
215
fXX
• Fixed time interval (
= 7.81 ms : at 4.19 MHz operation) interrupt generation
If pulse output is not necessary, the PPO pin can be used as a 1-bit output port.
Note If the STOP mode is set while the timer/pulse generator is in operation, miss-operation may result.
To prevent that from occurring, preset the timer/pulse generator to the stop state using its mode
register.
Fig. 5-5 Block Diagram of Timer/Pulse Generator (Timer Mode)
Internal Bus
8
8
MODL
MODH
Modulo Register L (8)
Modulo Register H (8)
TPGM3
(Set to "1")
INTTPG
IRQTPG
Set Signal
Modulo Latch H (8)
8
Match
Output Buffer
PPO
Comparator (8)
8
T F/F
Selector
Set
Frequency
Divider
CP
fX
1/2
Prescalar Select Latch (5)
Clear
Count Register (8)
Clear
TPGM4 TPGM5 TPGM7
TPGM1
22
NEC [ NEC ]
