Datasheet

MCP7940N
DS20005010F-page 50  2010-2014 Microchip Technology Inc.
APPENDIX A: REVISION HISTORY
Revision A (04/2011)
Original release of this document.
Revision B (09/2011)
• Added Figure 1-2
• Added Parameter D15 to Table 1-1
• Added Section 3.3 “Oscillator Input/Output
(X1, X2)”, Section 3.4 “Multifunction Pin
(MFP)”, Section 3.5 “Backup Supply (Vbat)”
• Added Figure 5-1
• Updated Section 5.2.3 “Oscillator Failure Sta-
tus”, Section 5.2.4 “Crystal Specs”,
Section 5.2.5 “Power-fail Time-stamp”.
Revision C (12/2011)
Added DC/AC Char. Charts.
Revision D (11/2012)
Added Extended Temp.
Revision E (01/2013)
Revised Table 1-2: AC Characteristics; temperature
range
Revision F (03/2014)
Updated overall content for improved clarity. Added
detailed descriptions of registers. Updated block dia-
gram and application schematic.
Defined names for all bits and registers, and renamed
the bits shown in Tabl e 7-1 for clarification.
Renamed the DC characteristics shown in Table 7 -2 for
clarification.
TABLE 7-1: BIT NAME CHANGES
TABLE 7-2: DC CHARACTERISTIC NAME CHANGES
Old Bit Name New Bit Name
OSCON OSCRUN
VBAT PWRFAIL
LP LPYR
SQWE SQWEN
ALM0 ALM0EN
ALM1 ALM1EN
RS0 SQWFS0
RS1 SQWFS1
RS2 CRSTRIM
CALIBRATION TRIMVAL<6:0>
ALM0POL ALMPOL
ALM1POL ALMPOL
ALM0C<2:0> ALM0MSK<2:0>
ALM1C<2:0> ALM1MSK<2:0>
Old Name Old Symbol New Name New Symbol
Operating current SRAM I
CC Read SRAM/RTCC register operating current ICCREAD
ICC Write ICCWRITE
Operating current IVCC Timekeeping current ICCT
IBAT Timekeeping backup current IBATT
Standby current ICCS VCC data retention current (oscillator off) ICCDAT