Datasheet

 2012-2018 Microchip Technology Inc. DS20002300C-page 19

MCP7951X/MCP7952X

U-0 U-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-1

— — OSCRUN PWRFAIL VBATEN WKDAY2 WKDAY1 WKDAY0

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is clear x = Bit is unknown

bit 7-6 Unimplemented: Read as ‘0’

bit 5 OSCRUN: Oscillator Status bit

1 = Oscillator is enabled and running

0 = Oscillator has stopped or has been disabled

bit 4 PWRFAIL: Power Failure Status bit

(1,2)

1 = Primary power was lost and the power-fail timestamp registers have been loaded (must be cleared

in software). Clearing this bit resets the power-fail timestamp registers to ‘0’.

0 = Primary power has not been lost

bit 3 VBATEN: External Battery Backup Supply (VBAT) Enable bit

1 = VBAT input is enabled

0 = V

BAT input is disabled

bit 2-0 WKDAY<2:0>: Binary-Coded Decimal Value of Day of Week

Contains a value from 1 to 7. The representation is user-defined.

Note 1: The PWRFAIL bit must be cleared to log new timestamp data. This is to ensure previous timestamp data is

not lost.

2: The PWRFAIL bit can be cleared by writing a ‘0’. Once cleared, the PWRFAIL bit cannot be written to a ‘1’

in software.

U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-1

— — DATETEN1 DATETEN0 DATEONE3 DATEONE2 DATEONE1 DATEONE0

bit 7 bit 0

Legend:

R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’

-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is clear x = Bit is unknown

bit 7-6 Unimplemented: Read as ‘0’

bit 5-4 DATETEN<1:0>: Binary-Coded Decimal Value of Date’s Tens Digit

Contains a value from 0 to 3

bit 3-0 DATEONE<3:0>: Binary-Coded Decimal Value of Date’s Ones Digit

Contains a value from 0 to 9