at75c220 ATMEL Corporation, at75c220 Datasheet - Page 142

• Manufacturer Part Number: at75c220
• Description: Smart Internet Appliance Processor Siap
• Manufacturer: ATMEL Corporation

WD Clock Mode Register
Name:
Access:
Reset Value:0
•
•
•
WD Control Register
Name:
Access:
•
142
WDCLKS: Clock Selection
HPCV: High Preload Counter Value
CKEY: Clock Access Key
RSTKEY: Restart Key
0
0
1
1
WDCLKS
Counter is preloaded when watchdog counter is restarted with bits 0 to 11 set (FFF) and bits 12 to 15 equaling HPCV.
Used only when writing WD_CMR. CKEY is read as 0.
0x06E: Write access in WD_CMR is allowed.
Other value: Write access in WD_CMR is prohibited.
0xC071 = Watchdog counter is restarted.
Other value = No effect.
CKEY
31
23
15
31
23
15
–
–
7
–
–
7
0
1
0
1
WD_CMR
Read/write
WD_CR
Write-only
Clock Selected
ACLK/8
ACLK/32
ACLK/128
ACLK/1024
30
22
14
30
22
14
–
–
6
–
–
–
6
AT75C220
29
21
13
29
21
13
–
–
5
–
–
5
28
20
12
28
20
12
–
–
4
–
–
4
RSTKEY
RSTKEY
CKEY
HPCV
27
19
11
27
19
11
–
–
3
–
–
3
26
18
10
26
18
10
–
–
2
–
–
2
25
17
25
17
–
–
9
1
–
–
9
1
WDCLKS
24
16
24
16
–
–
8
0
–
–
8
0