MCP795WXX/MCP795BXX
REGISTER 5-4:
HOUR 0X03
RW RW
12/24
RW
RW
RW
CALSGN
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
CALSGN
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 ‘1’ enables 12-hour format.
bit 5
bit 4
10 Hour (AM/PM bit for 12-hour time)
10 Hour
bit 3-0 Hour
Note: 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
U
R
RW
RW
RW
Day
OSCON
bit 5
VBAT
VBATEN
bit 7
bit 6
bit 4
bit 3
bit 2
bit 0
Legend: R = Readable Bit W = Writable Bit U = Unimplemented bit, Read as ‘0’
bit 7-6 Unimplemented bit, read as ‘0’
bit 5
Bit 5 is the OSCON bit. This 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 fre-
quency. The bit will wait 32 oscillator cycles before the bit is set.
bit 4
bit 3
Bit 4 is the VBAT 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.
Bit 3 is the VBATEN 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.
bit 2-0 Day
Note:
Contains the BCD day. The range is 1-7. Also, additional bits are used for configuration and Status.
2011 Microchip Technology Inc.
Preliminary
DS22280A-page 13