mc33789 Freescale Semiconductor, Inc, mc33789 Datasheet - Page 61

• Manufacturer Part Number: mc33789
• Description: Airbag System Basis Chip Sbc With Power Supply And Psi5 Sensor Interface
• Manufacturer: Freescale Semiconductor, Inc

Table 26. SPI Command, - SAFE_THx
Watchdog Control SPI Commands
WDOG_FEED (0x4E, 0x8E)
used to service the watchdog.
other values are ignored by the logic.
response with all data bits set to '0'.
an ERROR response with the RE bit set to '1'.
Analog Integrated Circuit Device Data
Freescale Semiconductor
Default
→
Read *
Write
The WDOG_FEED command is a write-only command
Only watchdog 'high' or watchdog 'low' is accepted, any
The 33789 responds to the command is a fixed write
Any attempted read access to WDOG_FEED will result in
0x45,0x85
0x46,0x86
0x47,0x87
0x48,0x88
0x49,0x89
Comman
0x4A,0x8
0x4B,0x8
0x4C,0x8
SO **
SO
SO
C
d
A
B
SI
SI
* Response when [T_UNLOCK register value] = [DE, T6:T0]^0xAD
** Response when any of the following conditions exist (ERROR with RE = 1)
THRESHOLD
DE
A3
15
0
0
0
1
0
0
0
0
1
1
1
1
1
0
1
T6:T0
1 Previous SPI command was not T_UNLOCK write
2 [T_UNLOCK register value] <> [DE, T6:T0]^0xAD
3 Not in Start-up Mode
Dwell Extension = 255 ms
Dwell Extension = 2 s
A2
14
1
0
0
0
1
1
1
1
0
0
0
0
1
7-bit Safing Threshold data
A1
13
0
1
0
0
0
0
1
1
0
0
1
1
0
12
A0
P
P
P
0
0
1
0
1
0
1
0
1
0
Safing Threshold 0 Command
Safing Threshold 1 Command
Safing Threshold 2 Command
Safing Threshold 3 Command
Safing Threshold 4 Command
Safing Threshold 5 Command
Safing Threshold 6 Command
Safing Threshold 7 Command
SAFE_THx (0x45~0x4C, 0x85~0x8C)
11
A3
A3
1
1
1
Safing Threshold
10
A2
A2
1
1
1
Dwell Extension
A1
A1
9
1
1
1
A0
A0
8
0
0
0
Function
DE
DE
DE
SENSOR MESSAGE, OPERATION COMMAND AND SPI
7
0
x
T6
T6
T6
6
0
x
T5
T5
T5
5
0
x
FUNCTIONAL DEVICE OPERATION
T4
T4
T4
4
0
x
T3
T3
T3
3
0
x
T2
T2
T2
2
0
x
T1
T1
T1
1
1
x
33789
T0
T0
T0
0
0
x
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