Crc_Baicheva_Calc(); Description; Actions; Prototype - Infineon SP37 Function Manual

2.25

CRC_Baicheva_Calc()

2.25.1

Description

This function calculates a 8-bit CRC checksum for a memory area in RAM using a fixed polynomial
8 5 3 2
(x +x +x +x +x+1). It supports the standardized TPMS data protocol from the German Association of the
Automotive Industry (VDA) and is optimal for data word length of 119 bits and below. The CRC Baicheva
calculation starts with a defined preload value. The VDA protocol requires that a preload value of AA
2.25.2

Actions

• Calculate CRC Baicheva
2.25.3

Prototype

unsigned char CRC_Baicheva_Calc(unsigned char Preload, unsigned char idata * BlockStart, unsigned char
BlockLength)
2.25.4

Inputs

Table 109 CRC_Baicheva_Calc: Input Parameters
Register / Address
R7
R5
R3
2.25.5

Outputs

Table 110 CRC_Baicheva_Calc: Output values
Register/ Address
R7
2.25.6

Resource Usage

Table 111 CRC8_Baicheva_Calc: Resources
Type
Registers
ROM Library Function Guide
Type Name
unsigned char Preload
unsigned char BlockStart
idata*
unsigned char BlockLength
Type Name
unsigned char CRC_Result
Used or Modified
R0, R3, R5, R6, R7
Tire Pressure Monitoring Sensor
Description
Preload Value for the CRC Calculation.
According to VDA protocol value AA
Pointer to first Byte of the Data that is to be used
for calculating checksum.
Length in Bytes of Block that is used for
calculation of the checksum, starting with
*BlockStart.
Description
Calculated CRC Baicheva checksum
95
SP37
ROM Library Functions
be used.
H
is used.
H
Revision 1.0, 2011-12-15