l99h01 STMicroelectronics, l99h01 Datasheet - Page 37

• Manufacturer Part Number: l99h01
• Description: Motor Bridge Driver For Automotive Applications
• Manufacturer: STMicroelectronics

L99H01
4.4.1
Note:
SPI clock monitor and watchdog
Figure 11. Global error flag diagram
1. Writing a “1” to RWD - bit in ApplRegx restarts the internal watchdog counter.
The clock monitor counts the number of clock pulses during a communication frame (while
CSN is low). If the number of SCK pulses does not correspond with the frame width
indicated in the <SPI-frame-ID> (ROM address 03hex) the frame is ignored and the bit
<frame error> in the <Global Status Byte> is set.
Due to this safety functionality, daisy chaining the SPI is not possible. Instead, a parallel
operation of the SPI bus by controlling the CSN signal of the connected ICs is
recommended.
SDO / Err
CSN
SCK
SDI
Global Error Flag
Doc ID 15567 Rev 3
WD counter
ApplRegx
Clock-
Monitor
RWD
bit 7
(1)
Communication Error
Watchdog Failure
Global Status Byte
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