PIC32MX440F256H-80I Datasheet, PDF (488/646 Pages) Microchip Technology – 64/100-Pin General Purpose and USB 32-Bit Flash Microcontrollers

PIC32MX3XX/4XX
21.6 I/O Pin Control
Enabling the RTCC modules configures the I/O pin
direction. When the RTCC module is enabled, config-
ured and the output enabled, the I/O pin direction is
properly configured as a digital output.
The RTCC pin can be configured to toggle at every
alarm or “seconds” event. To enable the RTCC pin out-
put, set the RTCOE bit (RTCCON<0>) = 1. To select
the output to toggle on an alarm event, configure
RTSECSEL bit (RTCCON<7>) = 0. To select the output
to toggle on every “seconds” update, configure
RTSECSEL bit = 1.
TABLE 21-3: I/O PIN CONFIGURATION FOR USE WITH RTCC MODULE
Required Settings for Module Pin Control
IO Pin
Name
Required
Module
Control
Bit
Field
TRIS⁽⁴⁾
Pin
Type
Buffer
Type
Description
ON
RTCC Seconds Clock
RTCC
Yes⁽¹⁾
and RTSECSEL = 1 X
O
CMOS
RTCOE⁽²⁾
ON
RTCC Alarm Pulse
RTCC
Yes⁽¹⁾
and RTSECSEL = 0 X
O
CMOS
RTCOE⁽²⁾ and ALRMEN
and PIV⁽³⁾
Legend: CMOS = CMOS compatible input or output; ST = Schmitt Trigger input with CMOS levels; I = Input;
O = Output
Note 1: The RTCC pin is only required when seconds clock or alarm pulse output is needed. Otherwise, this pin can
be used for general purpose IO and require the user to set the corresponding TRIS control register bit.
2: The ON (RTCCON<15>) and RTCOE (RTCCON<0>) bits are always required to validate the output function
of the RTCC pin, either seconds clock or alarm pulse.
3: When RTSECSEL (RTCCON<7>) = 0, the RTCC pin output is the alarm pulse. If the ALRMEN
(RTCALRM<15>) = 0, PIV (RTCALRM<13>) selects the value at the RTCC pin. When the ALRMEN = 1, the
RTCC pin reflects the state of the alarm pulse.
4: The setting of the TRIS bit is irrelevant.
DS61143E-page 486
Preliminary
© 2008 Microchip Technology Inc.