Datasheet

 2013 Microchip Technology Inc. DS22331A-page 75
MCP19111
11.3.0.1 OPTION Register
The OPTION register is a readable and writable
register, which contains various control bits to
configure:
• Timer0/WDT prescaler
• External GPA2/INT interrupt
•Timer0
• Weak pull-ups on PORTGPA and PORTGPB
Note 1: To achieve a 1:1 prescaler assignment
for Timer0, assign the prescaler to the
WDT by setting PSA bit to ‘1’ of the
OPTION register. See Section 23.1.3
“Software Programmable Prescaler”
REGISTER 11-2: OPTION_REG: OPTION REGISTER (Note 1)
R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
RAPU
INTEDG T0CS
T0SE PSA PS2 PS1 PS0
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 cleared x = Bit is unknown
bit 7 RAPU
: Port GPx Pull-up Enable bit
1 = Port GPx pull-ups are disabled
0 = Port GPx pull-ups are enabled
bit 6 INTEDG: Interrupt Edge Select bit
0 = Interrupt on rising edge of INT pin
1 = Interrupt on falling edge of INT pin
bit 5 T0CE: TMR0 Clock Source Select bit
1 = Transition on T0CKI pin
0 = Internal instruction cycle clock
bit 4 T0SE: TMR0 Source Edge Select bit
1 = Increment on high-to-low transition on T0CKI pin
0 = Increment on low-to-high transition on T0CKI pin
bit 3 PSA: Prescaler Assignment bit
1 = Prescaler is assigned to WDT
0 = Prescaler is assigned to the Timer0 module
bit 2-0 PS<2:0>: Prescaler Rate Select bits
Note 1: Individual WPUx bit must also be enabled.
Bit Value
TMR0
Rate
WDT Rate
000 1: 2 1: 1
001 1: 4 1: 2
010 1: 8 1: 4
011 1: 16 1: 8
100 1: 32 1: 16
101 1: 64 1: 32
110 1: 128 1: 64
111 1: 256 1: 128