UPD75208 NEC, UPD75208 Datasheet - Page 19

• Manufacturer Part Number: UPD75208
• Description: 4-BIT SINGLE-CHIP MICROCOMPUTER
• Manufacturer: NEC

5.6
generator. The timer/pulse generator has the following functions:
Note
f
The PD75208 incorporates one channel of timer/pulse generator which can be used as a timer or a pulse
(a)
(b)
If pulse output is not necessary, the PPO pin can be used as a 1-bit output port.
(Set to "1")
X
Frequency
Divider
TPGM3
TPGM1
TIMER/PULSE GENERATOR
1/2
If the STOP mode is set while the timer/pulse generator is in operation, erroneous operation may result.
To prevent that from occurring, preset the timer/pulse generator to the stop state using its mode
register.
Functions available in the PWM pulse generate mode
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
• 14-bit accuracy PWM pulse output to the PPO pin (Used as a digital-to-analog converter and applicable
• Fixed time interval (
to tuning)
Fig. 5-5 Block Diagram of Timer/Pulse Generator (Timer Mode)
Prescalar Select Latch (5)
Modulo Register L (8)
2
f
XX
15
8
= 7.81 ms : at 4.19 MHz operation) interrupt generation
Clear
MODL
Internal Bus
CP
Modulo Register H (8)
Modulo Latch H (8)
Count Register (8)
Comparator (8)
8
8
8
Clear
Match
MODH
T F/F
Set
TPGM4 TPGM5 TPGM7
Selector
INTTPG
IRQTPG
Set Signal
PD75208
Output Buffer
PPO
19