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DRAFT DRAFT DR
DRAFT DRAFT DRAFT
D
RAF
DRAFT DRAFT DRA
FT D
RAFT DR
AFT D
DRA
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D
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UM10601
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2012. All rights reserved.
Preliminary user manual
Rev. 1.0 — 7 November 2012
227 of 313
18.1 How to read this chapter
The CRC engine is available on all LPC800 parts.
18.2 Features
•
Supports three common polynomials CRC-CCITT, CRC-16, and CRC-32.
–
CRC-CCITT: x
16
+ x
12
+ x
5
+ 1
–
CRC-16: x
16
+ x
15
+ x
2
+ 1
–
CRC-32: x
32
+ x
26
+ x
23
+ x
22
+ x
16
+ x
12
+ x
11
+ x
10
+ x
8
+ x
7
+ x
5
+ x
4
+ x
2
+ x + 1
•
Bit order reverse and 1’s complement programmable setting for input data and CRC
sum.
•
Programmable seed number setting.
•
Supports CPU PIO back-to-back transfer.
•
Accept any size of data width per write: 8, 16 or 32-bit.
–
8-bit write: 1-cycle operation
–
16-bit write: 2-cycle operation (8-bit x 2-cycle)
–
32-bit write: 4-cycle operation (8-bit x 4-cycle)
18.3 Basic configuration
Enable the clock to the CRC engine in the SYSAHBCLKCTRL register (
, bit 13).
18.4 Pin description
The CRC engine has no configurable pins.
18.5 General description
The Cyclic Redundancy Check (CRC) generator with programmable polynomial settings
supports several CRC standards commonly used.
UM10601
Chapter 18: LPC800 Cyclic Redundancy Check (CRC) engine
Rev. 1.0 — 7 November 2012
Preliminary user manual