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R01UH0336EJ0102 Rev.1.02
Page 396 of 1538
Jul 17, 2014
V850E2/PG4-L
Section 12 Window Watchdog Timer A (WDTA)
(2)
WDTA Mode Register (WDTAnMD)
This register specifies the overflow time, the 75% interrupt output mode, the
error mode, and the window-open period.
It can be updated only once after reset release and before the first trigger. The
updated value is effective after the next WDTA trigger.
Updating this register after the WDTA has been started leads to error
detection, but the read value of this register can be written without generating
an error.
Access
This register can be read/written in 8-bit units.
Address
<WDTAn_base> + 000C
H
Initial value
7F
H
This register is initialized by any reset sources.
7
6
5
4
3
2
1
0
0
WDTAnOVF[2:0]
WDTAnWIE WDTAnERM
WDTAnWS[1:0]
R
*
R/W
R/W
R/W
R/W
R/W
R/W
R/W
*
Writing to this bit is ignored, reading returns 0.
Table 12-8
WDTAnMD Register Contents
Bit Position
Bit Name
Function
6 to 4
WDTAnOVF[2:0]
Selects the overflow time.
WDTAnOVF
2
WDTAnOVF
1
WDTAnOVF
0
Overflow Time
0
0
0
2.048 ms
0
0
1
4.096 ms
0
1
0
8.192 ms
0
1
1
16.384 ms
1
0
0
32.768 ms
1
0
1
65.536 ms
1
1
0
131.072 ms
1
1
1
262.144 ms
3
WDTAnWIE
Enables/disables the 75% interrupt request WDTAnTIT.
0: WDTAnTIT disabled
1: WDTAnTIT enabled
2
WDTAnERM
Specifies the error mode.
0: NMI request mode
1: Reset mode
1, 0
WDTAnWS[1:0]
Selects the period over which the window is open.
WDTAnWS1
WDTAnWS0
Window-Open Period
0
0
25%
0
1
50%
1
0
75%
1
1
100%