PIC24FJ128GA MICROCHIP [Microchip Technology], PIC24FJ128GA Datasheet - Page 163

• Manufacturer Part Number: PIC24FJ128GA
• Description: General Purpose, 16-Bit Flash Microcontrollers
• Manufacturer: MICROCHIP [Microchip Technology]

19.0
The programmable CRC generator offers the following
features:
• User-programmable polynomial CRC equation
• Interrupt output
• Data FIFO
REGISTER 19-1:
© 2006 Microchip Technology Inc.
bit 15-14 Unimplemented: Read as ‘0’
bit 13
bit 12-8
bit 7
bit 6
bit 5
bit 4
bit 3-0
Upper Byte:
bit 15
U-0
—
PROGRAMMABLE CYCLIC
REDUNDANCY CHECK (CRC)
GENERATOR
CSIDL: CRC Stop in Idle Mode bit
1 = Discontinue module operation when device enters Idle mode
0 = Continue module operation in Idle mode
VWORD4:VWORD0: Pointer Value bits
Indicates the number of valid words in the FIFO. Has a maximum value of 8 when PLEN3:PLEN0 > 7,
or 16 when PLEN3:PLEN0
CRCFUL: FIFO Full bit
1 = FIFO is full
0 = FIFO is not full
CRCMPT: FIFO Empty Bit
1 = FIFO is empty
0 = FIFO is not empty
Unimplemented: Read as ‘0’
CRCGO: Start CRC bit
1 = Start CRC serial shifter
0 = CRC serial shifter turned off
PLEN3:PLEN0: Polynomial Length bits
Denotes the length of the polynomial to be generated minus 1.
Legend:
R = Readable bit
-n = Value at POR
Lower Byte:
bit 7
U-0
CRCFUL
—
R-0
CRCCON: CRC CONTROL REGISTER
CSIDL
R/W-0
CRCMPT
R-1
≤
‘1’ = Bit is set
VWORD4
W = Writable bit
7.
R-0
U-0
—
Preliminary
VWORD3
R-0
PIC24FJ128GA FAMILY
CRCGO
R/W-0
19.1
There are four registers used to control programmable
CRC operation:
• CRCCON
• CRCXOR
• CRCDAT
• CRCWDAT
VWORD2
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
R-0
PLEN3
R/W-0
Registers
VWORD1
R-0
PLEN2
R/W-0
VWORD0
x = Bit is unknown
R-0
PLEN1
bit 8
R/W-0
DS39747C-page 161
PLEN0
R/W-0
bit 0