W83977G Winbond Electronics Corp America, W83977G Datasheet - Page 109

• Manufacturer Part Number: W83977G
• Description: W83877TF plus KBC, CIR, RTC, Pb-free
• Manufacturer: Winbond Electronics Corp America

UE
A "1" on this bit enables the update-ended flag (UF) bit in register C to assert an interrupt.
A "0" on this bit prohibits update-ended interrupt. The UE bit is cleared by setting the SET bit or by a
RESET.
DM
The data mode bit determines whether time and calendar updates are in binary format or in binary-
coded-decimal (BCD) format.
A "1" on this bit means binary format.
A "0" on this bit means BCD format. This bit can not be modified by a RESET or any internal function.
24/12
A "1" on this bit selects 24-hour mode for the time-of-day function.
A "0" on this bit selects 12-hour mode. This bit can not be modified by a RESET or any internal
function.
DSE
A "1" on this bit allows two special updates:
A "0" on this bit disables these special updates. DSE can not be changed by any internal operation or
9.3.3
IRQF
The interrupt request flag is set to a "1" if one or more of following cases are true:
PF*PE = "1"
AF*AE = "1"
UF*UE = "1"
(i.e., IRQF = PF*PE + AF*AE + UF*UE)
Any time the IRQF bit is a "1", the IRQ is asserted (provided LD4-CR70 and LD4-CR71 are set
properly). All flags are cleared by reading the register or by a RESET.
PF
The periodic interrupt flag is set to "1" when a rising edge is detected on the selected tap of the divider
chain(RS[3:0] of register A). PF is set to a "1" regardless of the state of PE bit. This bit is cleared by a
RESET or when this register is read.
AF
A "1" on this bit indicates that the current time has reached the alarm time setting (alarm A). A
RESET or a read of this register clears this bit.
(Note: RTC IRQ is ultimately controlled by Logical Device 4-CR70 and Logical Device 4-CR71. These two registers must be
NAME
BIT
W83977F-A/ W83977G-A/ W83977AF-A/ W83977AG-A
• On the last Sunday of April, the time increments from 1:59:59 AM to 3:00:00 AM.
• On the last Sunday of October, the time decrements from 1:59:59 AM to 1:00:00 AM.
a RESET.
set properly if RTC IRQ is needed)
Register 0Ch (Read only)
IRQF
7
PF
6
AF
5
-101 -
UF
4
3
0
Publication Release Date: May 2006
2
0
0
1
Revision 0.60
0
0