Datasheet

PIC12(L)F1501
DS41615A-page 170 Preliminary  2011 Microchip Technology Inc.
22.1.5 CLCx SETUP STEPS
The following steps should be followed when setting up
the CLCx:
• Disable CLCx by clearing the LCxEN bit.
• Select desired inputs using CLCxSEL0 and
CLCxSEL1 registers (See Table 22-1).
• Clear any associated ANSEL bits.
• Set all TRIS bits associated with inputs.
• Clear all TRIS bits associated with outputs.
• Enable the chosen inputs through the four gates
using CLCxGLS0, CLCxGLS1, CLCxGLS2, and
CLCxGLS3 registers.
• Select the gate output polarities with the
LCxPOLy bits of the CLCxPOL register.
• Select the desired logic function with the
LCxMODE<2:0> bits of the CLCxCON register.
• Select the desired polarity of the logic output with
the LCxPOL bit of the CLCxPOL register. (This
step may be combined with the previous gate out-
put polarity step).
• If driving the CLCx pin, set the LCxOE bit of the
CLCxCON register and also clear the TRIS bit
corresponding to that output.
• If interrupts are desired, configure the following
bits:
- Set the LCxINTP bit in the CLCxCON register
for rising event.
- Set the LCxINTN bit in the CLCxCON
register or falling event.
- Set the CLCxIE bit of the associated PIE
registers.
- Set the GIE and PEIE bits of the INTCON
register.
• Enable the CLCx by setting the LCxEN bit of the
CLCxCON register.
22.2 CLCx Interrupts
An interrupt will be generated upon a change in the
output value of the CLCx when the appropriate interrupt
enables are set. A rising edge detector and a falling
edge detector are present in each CLC for this purpose.
The CLCxIF bit of the associated PIR registers will be set
when either edge detector is triggered and its associated
enable bit is set. The LCxINTP enables rising edge inter-
rupts and the LCxINTN bit enables falling edge inter-
rupts. Both are located in the CLCxCON register.
To fully enable the interrupt, set the following bits:
• LCxON bit of the CLCxCON register
• CLCxIE bit of the associated PIE registers
• LCxINTP bit of the CLCxCON register (for a rising
edge detection)
• LCxINTN bit of the CLCxCON register (for a fall-
ing edge detection)
• PEIE and GIE bits of the INTCON register
The CLCxIF bit of the associated PIR registers, must
be cleared in software as part of the interrupt service. If
another edge is detected while this flag is being
cleared, the flag will still be set at the end of the
sequence.
22.3 Output Mirror Copies
Mirror copies of all LCxCON output bits are contained
in the CLCxDATA register. Reading this register reads
the outputs of all CLCs simultaneously. This prevents
any reading skew introduced by testing or reading the
CLCxOUT bits in the individual CLCxCON registers.
22.4 Effects of a Reset
The CLCxCON register is cleared to zero as the result
of a Reset. All other selection and gating values remain
unchanged.
22.5 Operation During Sleep
The CLC module operates independently from the
system clock and will continue to run during Sleep,
provided that the input sources selected remain active.
The HFINTOSC remains active during Sleep when the
CLC module is enabled and the HFINTOSC is
selected as an input source, regardless of the system
clock source selected.
In other words, if the HFINTOSC is simultaneously
selected as the system clock and as a CLC input
source, when the CLC is enabled, the CPU will go idle
during Sleep, but the CLC will continue to operate and
the HFINTOSC will remain active.
This will have a direct effect on the Sleep mode current.
22.6 Alternate Pin Locations
This module incorporates I/O pins that can be moved to
other locations with the use of the alternate pin function
register, APFCON. To determine which pins can be
moved and what their default locations are upon a
Reset, see
Section 11.1 “Alternate Pin Function” for
more information.