Microchip Technology MA330031-2 데이터 시트
2011-2013 Microchip Technology Inc.
DS70000657H-page 373
dsPIC33EPXXXGP50X, dsPIC33EPXXXMC20X/50X AND PIC24EPXXXGP/MC20X
26.0
PROGRAMMABLE CYCLIC
REDUNDANCY CHECK (CRC)
GENERATOR
REDUNDANCY CHECK (CRC)
GENERATOR
The programmable CRC generator offers the following
features:
• User-programmable (up to 32nd order)
features:
• User-programmable (up to 32nd order)
polynomial CRC equation
• Interrupt output
• Data FIFO
The programmable CRC generator provides a
hardware implemented method of quickly generating
checksums for various networking and security
applications. It offers the following features:
• User-programmable CRC polynomial equation,
• Data FIFO
The programmable CRC generator provides a
hardware implemented method of quickly generating
checksums for various networking and security
applications. It offers the following features:
• User-programmable CRC polynomial equation,
up to 32 bits
• Programmable shift direction (little or big-endian)
• Independent data and polynomial lengths
• Configurable interrupt output
• Data FIFO
A simplified block diagram of the CRC generator is
shown in
• Independent data and polynomial lengths
• Configurable interrupt output
• Data FIFO
A simplified block diagram of the CRC generator is
shown in
. A simple version of the CRC shift
engine is shown in
FIGURE 26-1:
CRC BLOCK DIAGRAM
Note 1:
This data sheet summarizes the
features of the dsPIC33EPXXXGP50X,
dsPIC33EPXXXMC20X/50X and
PIC24EPXXXGP/MC20X families of
devices. It is not intended to be a compre-
hensive reference source. To complement
the information in this data sheet, refer to
“Programmable Cyclic Redundancy
Check (CRC)”
features of the dsPIC33EPXXXGP50X,
dsPIC33EPXXXMC20X/50X and
PIC24EPXXXGP/MC20X families of
devices. It is not intended to be a compre-
hensive reference source. To complement
the information in this data sheet, refer to
“Programmable Cyclic Redundancy
Check (CRC)”
(DS70346) of the
“dsPIC33/PIC24 Family Reference Man-
ual
ual
”, which is available from the Microchip
www.microchip.com
).
2:
Some registers and associated bits
described in this section may not be
available on all devices. Refer to
described in this section may not be
available on all devices. Refer to
in
this data sheet for device-specific register
and bit information.
and bit information.
Variable FIFO
(4x32, 8x16 or 16x8)
CRCDATH
CRCDATL
Shift Buffer
CRC Shift Engine
CRCWDATH
CRCWDATL
LENDIAN
1
0
CRCISEL
1
0
FIFO Empty Event
Shift Complete Event
Set CRCIF
2 * F
P
Shift Clock