Datasheet

 2012-2018 Microchip Technology Inc. DS20002300C-page 27
MCP7951X/MCP7952X
5.5 MFP Output
The MCP795XX features Square Wave Clock Output
and Alarm Interrupt Output modes through the MFP
pin. If the SQWEN bit is set, then MFP operates in
Square Wave Clock Output mode.
The alarm outputs will remain active on the MFP pin
while operating from the backup power supply. The
Square Wave Clock Output is disabled while operating
from the backup power supply.
FIGURE 5-8: CLKOUT OUTPUT BLOCK DIAGRAM
5.5.1 SQUARE WAVE OUTPUT MODE
The MCP795XX can be configured to generate a
square wave clock signal on MFP. The input clock fre-
quency, F
OSC, is divided according to the
SQWFS<1:0> bits as shown in Tabl e 5-8.
The square wave output is not available when
operating from the backup power supply, but the
square wave settings can be retained by the backup
power supply so that the square wave output can
continue when V
CC is restored.
TABLE 5-8: CLOCK OUTPUT RATES
X2
X1
ST
Oscillator
EXTOSC
Postscaler
MUX
32.768 kHz
8.192 kHz
4.096 kHz
1 Hz
SQWFS<1:0>
11
10
01
00
Digital
Trim
1
0
CRSTRIM
MFP
0
1
SQWEN
Alarm Flags
MCP795XX
Note: All of the clock output rates are affected by
digital trimming except for the 1:1
postscaler value (SQWFS<1:0> = 11).
SQWFS<1:0> Postscaler
Nominal
Frequency
00 1:32,768 1 Hz
01 1:8 4.096 kHz
10 1:4 8.192 kHz
11 1:1 32.768 kHz
Note 1: Nominal frequency assumes F
OSC is
32.768 kHz.