Microchip Technology MA330019 Data Sheet
dsPIC33FJ32MC302/304, dsPIC33FJ64MCX02/X04 AND dsPIC33FJ128MCX02/X04
DS70291G-page 324
© 2007-2012 Microchip Technology Inc.
26.5
Programmable CRC Registers
REGISTER 26-1:
CRCCON: CRC CONTROL REGISTER
U-0
U-0
R/W-0
R-0
R-0
R-0
R-0
R-0
—
—
CSIDL
VWORD<4:0>
bit 15
bit 8
R-0
R-1
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
CRCFUL
CRCMPT
—
CRCGO
PLEN<3:0>
bit 7
bit 0
Legend:
R = Readable bit
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 15-14
Unimplemented: Read as ‘0’
bit 13
CSIDL: CRC Stop in Idle Mode bit
1 = Discontinue module operation when device enters Idle mode
0 = Continue module operation in Idle mode
1 = Discontinue module operation when device enters Idle mode
0 = Continue module operation in Idle mode
bit 12-8
VWORD<4:0>: Pointer Value bits
Indicates the number of valid words in the FIFO. Has a maximum value of 8 when PLEN<3:0> > 7,
Indicates the number of valid words in the FIFO. Has a maximum value of 8 when PLEN<3:0> > 7,
or 16 when PLEN<3:0>
≤
7.
bit 7
CRCFUL: FIFO Full bit
1 = FIFO is full
0 = FIFO is not full
1 = FIFO is full
0 = FIFO is not full
bit 6
CRCMPT: FIFO Empty Bit
1 = FIFO is empty
0 = FIFO is not empty
1 = FIFO is empty
0 = FIFO is not empty
bit 5
Unimplemented: Read as ‘0’
bit 4
CRCGO: Start CRC bit
1 = Start CRC serial shifter
0 = Turn off the CRC serial shifter after the FIFO is empty
1 = Start CRC serial shifter
0 = Turn off the CRC serial shifter after the FIFO is empty
bit 3-0
PLEN<3:0>: Polynomial Length bits
Denotes the length of the polynomial to be generated minus 1.
Denotes the length of the polynomial to be generated minus 1.