CHAPTER 8 WATCH TIMER
User’s Manual U13850EJ6V0UD
254
(1) Watch timer
The watch timer generates an interrupt request (INTWTN) at time intervals of 0.5 seconds or 0.25 seconds by
using the main clock or subclock.
(2) Interval timer
The watch timer generates an interrupt request (INTWTNI) at time intervals specified in advance.
Table 8-1. Interval Time of Interval Timer
Interval Time
f
XT
= 32.768 kHz
2
4
×
1/f
W
488
µ
s
2
5
×
1/f
W
977
µ
s
2
6
×
1/f
W
1.95 ms
2
7
×
1/f
W
3.91 ms
2
8
×
1/f
W
7.81 ms
2
9
×
1/f
W
15.6 ms
2
10
×
1/f
W
31.2 ms
2
11
×
1/f
W
62.4 ms
Remark
f
W
: Watch timer clock frequency
8.2 Configuration
The watch timer includes the following hardware.
Table 8-2. Configuration of Watch Timer
Item
Configuration
Counter
5 bits
×
1
Prescaler
11 bits
×
1
Control registers
Watch timer mode control register (WTNM)
Watch timer high-speed clock selection register (WTNHC)
Note
Watch timer clock selection register (WTNCS)
Note
The WTNHC register is available only in the B versions of the V850/SB1,
µ
PD703036H, 703036HY,
703037H, 703037HY, 70F3036H, 70F3036HY, 70F3037H, and 70F3037HY.
Содержание V850/SB1
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