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R01UH0336EJ0102 Rev.1.02
Page 388 of 1538
Jul 17, 2014
V850E2/PG4-L
Section 12 Window Watchdog Timer A (WDTA)
12.3 Functional Description
The WDTA generates a reset or a non-maskable interrupt if the 16-bit counter
overflows or if any other error condition is fulfilled. For a description of all error
conditions, refer to Section 12.3.3, Error Detection.
The counter is cleared and restarted every time a WDTA trigger occurs in the
window-open period. Refer to Section 12.3.2, WDTA Trigger, and Section
12.3.5, Window Function, for details.
At 75% of the counter overflow value, the WDTA can generate an interrupt
request (WDTAnTIT). Refer to section Section 12.3.4, 75% Interrupt Output,
for details.
12.3.1
WDTA after Reset Release
The counter value remains 0000
H
after reset release.
The counter is started with the first WDTA trigger.
(1)
WDTA Settings after Reset Release
The WDTA settings are as follows after reset release.
Change
WDTA settings
After the first trigger, the WDTA continues according to the settings of the
watchdog timer mode register (WDTAnMD).
To change the WDTA settings, WDTAnMD must be written before the first
trigger. Changing the value of WDTAnMD after the first trigger leads to an error
condition.
If the value in WDTAnMD is not changed before the first trigger, the WDTA will
operate with the initial value of WDTAnMD.
The settings of WDTAnMD apply after the first trigger.
Function
Setting
Remarks
Overflow time
2
16
/WDTATCKI
75% interrupt mode
Enabled
Error mode
Reset mode
Any error condition before the
first trigger generates a reset.
Window-open period
100%
Содержание V850 Series
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