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TLE5014
GMR-Based Angle Sensor
SICI
Table 14
Structure of the Safety Word
Name
Bits
STAT
Chip and Interface Status
[15]
[14]
[13]
[12]
RESP
[11..8]
CRC
[7..0]
6.2.3
CRC generation
The TLE5014 uses a cyclic redundancy check (CRC) to confirm the correct processing of read and write
commands via the safety word, and to monitor the integrity of configuration registers and EEPROM pages. The
CRC is generated according to the J1850 Bus-Specification:
•
Every new transfer resets the CRC generation
•
Every Byte of a transfer will be taken into account to generate the CRC (also the sent command(s))
•
Generator-Polynomial: X8+X4+X3+X2+1; for the CRC generation the fast-CRC generation circuit is used (see
Figure
10)
•
The remainder of the fast CRC circuit is initially set to '11111111
•
Remainder is inverted before transmission
Serial
X7
X6
1
CRC
output
Figure 10
Fast CRC polynomial division circuit
6.2.4
SICI Application Example: Reading working register
Sensor and micro controller must use an open-drain output, so they can actively pull only a 0 Volt level; the
5 Volt level is achieved by an external pull-up resistor.
User's Manual
Description
Indication of Chip-Reset or watchdog was activated
0: Reset occurred or watchdog was activated
1: No reset
System Error (e.g. Overvoltage; Undervoltage; GND- off; CRC)
0: Error occurred
1: No error
Interface Access Error (access to wrong address; wrong lock, wrong parity)
0: Error occurred
1: No error
Valid Angle Value (no ADC error, no internal plausibility check error)
0: Angle value invalid
1: Angle value valid
Sensor Number Response Indicator
The sensor number bit is pulled low and the other bits are high.
Cyclic Redundancy Check (CRC) includes command word, data words,
STAT & RESP
X5
X4
X3
xor
1
1
1
parallel
Remainder
'
B
X2
X1
1
1
xor
xor
36
X0
&
xor
1
1
Input
TX_CRC
Rev. 1.0
2019-03-12
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