33880_12 Datasheet, PDF (19/25 Pages) Freescale Semiconductor, Inc – Configurable Octal Serial Switch with Serial Peripheral Interface I/O

FUNCTIONAL DEVICE OPERATION
LOGIC COMMANDS AND REGISTERS
LOGIC COMMANDS AND REGISTERS
On each SPI communication, an 8-bit command word is sent to the 33880 and an 8-bit fault word is received from the 33880.
The Most Significant Bit (MSB) is sent and received first (see below).
MSB
LSB
OUT8 OUT7 OUT6 OUT5 OUT4
Command Register Definition:
0 = Output Command Off
1 = Output Command On
Fault Register Definition:
0 = No fault
1 = Fault.
OUT3
OUT2
OUT1
Table 6. Fault Operation
SERIAL OUTPUT (SO) PINS REPORTS
Overtemperature
Fault reported by Serial Output (DO) pin.
Overcurrent
DO pin reports short to battery/supply or overcurrent condition.
Output ON Open Load Fault
Not reported.
Output OFF Open Load Fault
DO pin reports output OFF open load condition.
DEVICE SHUTDOWNS
Overvoltage
Total device shutdown at V_PWR = 25 V to 30 V. Resumes normal operation with proper voltage.
All outputs assuming the previous state upon recovery from overvoltage.
Overtemperature
Only the output experiencing an overtemperature fault shuts down. Output assumes previous state
upon recovery from overtemperature.
Analog Integrated Circuit Device Data
Freescale Semiconductor
33880
19