UPD75218 NEC, UPD75218 Datasheet - Page 20

• Manufacturer Part Number: UPD75218
• Description: 4-BIT SINGLE-CHIP MICROCOMPUTER
• Manufacturer: NEC

20
5.6
generator. The timer/pulse generator has the following functions:
Note
Caution If the STOP mode is set while the timer/pulse generator is in operation, erroneous operation may result.
The PD75218 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.
f
(Set to 1)
X
Frequency
divider
TPGM3
TPGM1
TIMER/PULSE GENERATOR
7.81 ms when the microcomputer operates at 4.19 MHz
Functions available in the PWM pulse generation 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 (
1/2
To prevent that from occurring, preset the timer/pulse generator to the stop state using its mode
register.
to tuning)
Fig. 5-5 Block Diagram of Timer/Pulse Generator (Timer Mode)
Prescalar select latch (5)
Modulo register L (8)
2
f
X
15
= 5.46 ms when the microcomputer operates at 6.0 MHz)
8
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
Note
TPGM4 TPGM5 TPGM7
interrupt generation
Selector
INTTPG
IRQTPG
set signal
PD75218
Output buffer
PPO