MLX90363 Datasheet, PDF (33/57 Pages) Melexis Microelectronic Systems – Triaxis® Magnetometer IC With High Speed Serial Interface

14.17. EepromWrite Message
MLX90363
Triaxis® Magnetometer IC
With High Speed Serial Interface
#7 6 5 4 3 2 1 0 # 7 6 5 4 3 2 10
100
ADDRESS[5:0]⁽²²⁾
0
3
KEY[15:8]
2
KEY[7:0]
5
DATA WORD[15:8]
4
DATA WORD[7:0]
7
CRC
611000011
Table 36 – EEPROMWrite MOSI Message (Opcode = 3)
The EEPROM data consistency is guaranteed through two protection mechanisms: A and B.
Protection A: The parameter ADDRESS should match the parameter KEY.
The key associated to each address is public. Protection against erroneous write (in the field) is
guaranteed as long as the keys are not stored in the master (ECU), but in the calibration system, which is
typically a CAN or LIN Master.
Protection B: Slave challenges the Master with a randomly generated ChallengeKey, expects back this
key exclusive-or with 0x1234
MSC EEPROMWrite
MSC EEPROMWrite
(Case of Erroneous Key)
MSC EEPROMWrite
(Case of Failing Challenge)
Master
Slave
Master
Slave
Master
Slave
EEWrite(Addr,Key)( )
X ()
EEReadChallenge ( )
EEChallenge ()
EEChallengeAns ( )
EEReadAnswer ()
EEWrite(Addr,Key)( )
X ()
EEReadChallenge ( )
EEWriteStatus ()
EEWrite(Addr,Key)( )
X ()
EEReadChallenge ( )
EEChallenge ()
EEChallengeAnsr ( )
EEReadAnswer ()
tEEWrite
NOP ( )
EEWriteStatus ()
tEEWrite
NOP ( )
EEWriteStatus ()
ADDRESS[5:4]
0
1
2
3
0
17485
38105
55636
6368
1
31053
51302
64477
5907
Figure 19 – MSCs EEPROMWrite
ADDRESS[3:1]
2
3
4
57190
57724
7899
16209
24847
13134
40905
45498
24411
31384
63325
3562
5
53543
52339
36677
19816
6
26763
14530
4213
6995
Table 37 – EEPROM Write Public Keys
#7 6 5 4 3 2 1 0 # 7 6 5 4 3 2 10
1
0
3
2
5
4
7
CRC
611001111
Table 38 – EEPROMWrite ReadChallenge Slave-In Message (Opcode = 15)
7
12528
18350
48843
3147
22 _{The value of the ADDRESS[5:0] shall be even.}
3901090363
Rev. 005
Page 33 of 57
Data Sheet
Jul/13