MCP79510-IMS Datasheet, PDF (13/50 Pages) Microchip Technology – 3V SPI Real-Time Clock Calendar with Battery Switchover

MCP7952X/MCP7951X
REGISTER 5-4: HOUR 0X03
R/W
R/W
R/W
R/W
R/W
CALSGN
12/24
10 Hour
AM/PM
10 Hour
Hour
bit 7
bit 6
bit 5
bit 4
bit 3
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
bit 7
bit 6
bit 5
bit 4
bit 3-0
CALSGN: Calibration Sign bit
Bit 7 is the sign bit (CALSGN) for the calibration. Clearing this bit produces a positive calibration,
setting this bit produces a negative calibration.
12/24: Clearing this bit to ‘0’ enables 24-hour format, setting this bit to ‘1’ enables 12-hour format.
10 HOUR: AM/PM bit for 12-hour time
10 HOUR
HOUR<3:0>
Note 1: Contains the BCD hour in bits <3:0>. Bits <5:4> contain either the 10-hour in BCD for 24-hour format or
the AM/PM indicator and the 10-hour bit for 12-hour format. Bit 5 determines the hour format.
REGISTER 5-5: DAY 0X04
U-0
U-0
R
R/W
R/W
R/W
—
—
OSCON
VBAT
VBATEN
Day
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
bit 7-6
bit 5
bit 4
bit 3
bit 2-0
Unimplemented: Read as ‘0’
OSCON: Oscillator On bit
This bit is set and cleared by hardware. If this bit is set, the oscillator is running; if
clear, the oscillator is not running. This bit does not indicate that the oscillator is running at the correct
frequency. The bit will wait 32 oscillator cycles before the bit is set.
VBAT: External Battery Switched Flag bit
This bit is set by hardware when the VCC fails and the VBAT is used to power the oscillator and the
RTCC registers. This bit is cleared by software.
VBATEN: External Battery Enable bit
If this bit is set the internal circuitry is connected to the VBAT pin. If this bit is ‘0’ then the VBAT pin is
disconnected and the only current drain on the external battery is the VBAT pin leakage.
DAY<2:0>
Note 1: Contains the BCD day. The range is 1-7. Also, additional bits are used for configuration and status.
 2012 Microchip Technology Inc.
Preliminary
DS22300A-page 13