UPD78F9418A NEC, UPD78F9418A Datasheet - Page 132
UPD78F9418A
Manufacturer Part Number
UPD78F9418A
Description
(UPD7894xxA) 8-Bit Single Chip Microcontrollers
Manufacturer
NEC
Datasheet
1.UPD78F9418A.pdf
(319 pages)
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
UPD78F9418A
Manufacturer:
NEC
Quantity:
1 831
Part Number:
UPD78F9418AGC
Manufacturer:
NEC
Quantity:
20 000
Company:
Part Number:
UPD78F9418AGC-8BT-A
Manufacturer:
RENESAS
Quantity:
800
Company:
Part Number:
UPD78F9418AGC-8BT-A
Manufacturer:
Renesas Electronics America
Quantity:
10 000
Part Number:
UPD78F9418AGK-9EU
Manufacturer:
NEC
Quantity:
20 000
Company:
Part Number:
UPD78F9418AGK-9EU-A
Manufacturer:
Renesas Electronics America
Quantity:
10 000
- Current page: 132 of 319
- Download datasheet (3Mb)
www.DataSheet4U.com
8.4 Operation of Watch Timer
8.4.1 Operation as watch timer
interrupts at 0.5-second intervals.
starts counting. By setting them to 0, the 5-bit counter is cleared and the watch timer stops counting.
from 0 seconds. However, an error of up to 2
(INTWT) after a 0-second start, because the 9-bit prescaler is not cleared in this case.
8.4.2 Operation as interval timer
value.
132
Other than above
WTM6
The main system clock (4.19 MHz) or subsystem clock (32.768 kHz) is used as a watch timer that generates
By setting bits 0 and 1 (WTM0 and WTM1) of the watch timer mode control register (WTM) to 1, the watch timer
When the interval timer also operates at the same time by setting WTM1 to 0, only the watch timer can be started
The interval timer is used to repeatedly generate an interrupt request at the interval specified by a preset count
The interval time can be selected by bits 4 to 6 (WTM4 to WTM6) of the watch timer mode control register (WTM).
Remark
0
0
0
0
1
1
WTM5
0
0
1
1
0
0
f
f
f
X
XT
W
: Main system clock oscillation frequency
: Watch timer clock frequency
: Subsystem clock oscillation frequency
WTM4
0
1
0
1
0
1
2
2
2
2
2
2
Setting prohibited
4
5
6
7
8
9
× 1/f
× 1/f
× 1/f
× 1/f
× 1/f
× 1/f
W
W
W
W
W
W
Interval
Table 8-3. Interval Time of Interval Timer
CHAPTER 8 WATCH TIMER
User’s Manual U13952EJ3V0UD
9
× 1/f
409.6 µ s
819.2 µ s
1.64 ms
3.28 ms
6.55 ms
13.1 ms
W
f
Operation at
seconds may occur for the first overflow of the watch timer
X
= 5.0 MHz
489 µ s
978 µ s
1.96 ms
3.91 ms
7.82 ms
15.6 ms
f
Operation at
X
= 4.19 MHz
488 µ s
977 µ s
1.95 ms
3.91 ms
7.81 ms
15.6 ms
f
XT
Operation at
= 32.768 kHz
Related parts for UPD78F9418A
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
16BIT MCU, 128K FLASH, 8K RAM, SMD
Manufacturer:
NEC
Datasheet:
Part Number:
Description:
8BIT UC, 32K FLASH, 1KB RAM, LCD
Manufacturer:
NEC
Datasheet:
Part Number:
Description:
8BIT MCU, 60K FLASH, 3KB RAM, CAN
Manufacturer:
NEC
Datasheet:
Part Number:
Description:
8BIT MCU, 128K FLASH, 7K RAM, LQFP
Manufacturer:
NEC
Datasheet:
Part Number:
Description:
8BIT MCU, 4K FLASH, 128B RAM, SMD
Manufacturer:
NEC
Datasheet:
Part Number:
Description:
16/8 bit single-chip microcomputer
Manufacturer:
NEC
Datasheet:
Part Number:
Description:
Dual audio power amp circuit
Manufacturer:
NEC
Datasheet:
Part Number:
Description:
Dual comparator
Manufacturer:
NEC
Datasheet:
Part Number:
Description:
MOS type composite field effect transistor
Manufacturer:
NEC
Datasheet: