W83977AF Information Storage Devices, Inc, W83977AF Datasheet - Page 108

• Manufacturer Part Number: W83977AF
• Description: W83877TF Plus Kbc, Cir, RTC
• Manufacturer: Information Storage Devices, Inc

UPDATE CYCLE TIME TABLE
Update Period and UIP Timing
6.3 REGISTERS
The RTC has four control/status registers. They are accessible at all times.
6.3.1 Register 0Ah
UIP : (read only)
When UIP is 1, an update cycle is in progress. The UIP is cleared in the end of an update cycle and
when the SET bit in register B is 1.
All bits are unaffected by RESET.
Register A is a read/write register except bit 7 (UIP is read only).
NAME
UIP BIT
BIT
1
0
UIP
7
UPDATE CYCLE TIME (T
DV2
Update Period(1 Second)
6
1984 S
-
DV1
5
t
UC
BUC
)
- 96 -
DV0
4
BEFORE UPDATE CYCLE TIME (T
t
UC
RS3
3
W83977F/ W83977AF
Publication Release Date: January 1997
RS2
2
244 S
-
PRELIMINARY
RS1
1
Revision 0.50
BUC
RS0
MIN)
0