M16C62_M Datasheet, PDF (469/615 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/60 SERIES

CRC Calculation Circuit
Mitsubishi microcomputers
M16C / 62A Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
2.10 CRC Calculation Circuit Usage
2.10.1 Overview of the CRC calculation circuit usage
Cyclic Redundancy Check (CRC) is a method that compares CRC code formed from transmission data
by use of a polynomial generation with CRC check data so as to detect errors in transmission data. Using
the CRC calculation circuit allows generation of CRC code. A polynomial counter is used for the polyno-
mial generation of CRC_CCITT (X¹⁶ + X¹² + X⁵ + 1).
(1) Registers related to CRC calculation circuit
Figure 2.10.1 shows the memory map of CRC-related registers, and Figure 2.10.2 shows CRC- re-
lated registers.
03BC16
03BD16
03BE16
CRC data register (CRCD)
CRC input register (CRCIN)
Figure 2.10.1. Memory map of CRC-related registers
CRC data register
(b15)
b7
(b8)
b0 b7
b0
Symbol
CRCD
Address
When reset
03BD16, 03BC16 Indeterminate
Function
CRC calculation result output register
Values that
can be set
RW
000016 to FFFF16
CRC input register
b7
b0
Symbo
CRCIN
Data input register
Function
Address
03BE16
When reset
Indeterminate
Values that
can be set
0016 to FF16
RW
Figure 2.10.2. CRC-related registers
2-152