m48t86 STMicroelectronics, m48t86 Datasheet - Page 21

• Manufacturer Part Number: m48t86
• Description: 5v Pc Real Time Clock
• Manufacturer: STMicroelectronics

24/12
DSE: daylight savings enable
Table 6.
Figure 10. Update-ended/periodic interrupt relationship
Register C
IRQF: interrupt request flag
BIT7
SET
UIP
PF
UF
The 24/12 Control Bit establishes the format of the hours byte. A '1' indicates the 24-hour
mode and a '0' indicates the 12-hour mode. This bit is READ/WRITE and is not affected by
internal functions or RST.
The Daylight Savings Enable (DSE) Bit is a READ/WRITE bit which enables two special
updates when set to a '1.' On the first Sunday in April, the time increments from 1:59:59AM
to 3:00:00 AM. On the last Sunday in October, when the time reaches 1:59:59 AM, it
changes to 1:00:00 AM. These special updates do not occur when the DSE Bit is a '0.' This
bit is not affected by internal functions or RST.
Register B MSB
The Interrupt Request Flag (IRQF) Bit is set to a '1' when one or more of the following are
true:
PF = PIE = 1
AF = AIE = 1
UF = UIE = 1
(e.g., IRQF = PF*PIE+AF*AIE+UF*UIE)
BIT6
PIE
tPI
BIT5
AIE
tPI
BIT4
UIE
tPI
UPDATE PERIOD (1sec)
SQWE
BIT3
tBUC
BIT2
DM
tUC
24/12
BIT1
AI01652B
BIT0
DSE
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