PIC18F2420/2520/4420/4520
9.4
IPR Registers
The IPR registers contain the individual priority bits for
the peripheral interrupts. Due to the number of periph-
eral interrupt sources, there are two Peripheral Interrupt
Priority registers (IPR1 and IPR2). Using the priority bits
requires that the Interrupt Priority Enable (IPEN) bit be
set.
REGISTER 9-8:
IPR1: PERIPHERAL INTERRUPT PRIORITY REGISTER 1
R/W-1
PSPIP(1)
bit 7
R/W-1
ADIP
R/W-1
RCIP
R/W-1
TXIP
R/W-1
SSPIP
R/W-1
R/W-1
R/W-1
CCP1IP
TMR2IP
TMR1IP
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
bit 5
bit 4
PSPIP: Parallel Slave Port Read/Write Interrupt Priority bit(1)
1= High priority
0= Low priority
ADIP: A/D Converter Interrupt Priority bit
1= High priority
0= Low priority
RCIP: EUSART Receive Interrupt Priority bit
1= High priority
0= Low priority
TXIP: EUSART Transmit Interrupt Priority bit
1= High priority
0= Low priority
bit 3
bit 2
bit 1
bit 0
SSPIP: Master Synchronous Serial Port Interrupt Priority bit
1= High priority
0= Low priority
CCP1IP: CCP1 Interrupt Priority bit
1= High priority
0= Low priority
TMR2IP: TMR2 to PR2 Match Interrupt Priority bit
1= High priority
0= Low priority
TMR1IP: TMR1 Overflow Interrupt Priority bit
1= High priority
0= Low priority
Note 1: This bit is unimplemented on 28-pin devices and will read as ‘0’.
DS39631E-page 100
© 2008 Microchip Technology Inc.