33982B Datasheet, PDF (21/34 Pages) Freescale Semiconductor, Inc – Single Intelligent High-Current Self-Protected Silicon High-Side Switch (2.0 mohm)

FUNCTIONAL DEVICE OPERATION
LOGIC COMMANDS AND REGISTERS
C_CSS B
S^SCC^LL^KK
S^SI ^I
D7
D6
D5
S^SO^O
OD7
OD6
OD5
D2
D1
D0
D 7*
D 6*
D 5*
OD2
OD1
OD0
D7
D6
D5
D 2*
D 1*
D 0*
D2
D1
D0
Notes 1. RST is a Logic [1] state during the above operation. N O T E S : 1 .
2.
RR SSTT B i s i n a l o g i c 1 s t a t e d u r i n g t h e a b o v e o p e r a t i o n .
D 0 , D 1 , D 2 , ..., a n d D 7 re la te to th e m o s t re c e n t o rd e re d e n try o f d a ta in to th e S P S S
2. D7:D0 relate to the most recent ordered entry of data into the device. ^{3 .}
O D 0 , O D 1 , O D 2 , ..., a n d O D 7 r e la te to th e fir s t 8 b its o f o r d e r e d fa u lt a n d s ta tu s d a ta o u t o f th e d e v ic e .
4.
O D 0 , O D 1 , O D 2 , ..., a n d O D 7 re p re s e n t th e firs t 8 b its o f o rd e re d fa u lt a n d s ta tu s d a ta o u t o f th e S P S S
3. D7*:D0* relate to the previous 8 bits (last command word) of data that was previously shifted into the device.
4. OD7:OD0 relate to the firsFtI 8G bUitRs Eof 4obrd.erMedU fLauT lItPaLndE s8tabtiut sWdaOtaR oDutSoPf tIhCe OdeMviMceU. N I C A T I O N
Figure 10. Multiple 8-Bit Word SPI Communication
SERIAL INPUT COMMUNICATION
SPI communication is accomplished using 8-bit
messages. A message is transmitted by the MCU starting
with the MSB, D7, and ending with the LSB, D0 (Table 8).
Each incoming command message on the SI pin can be
interpreted using the following bit assignments: the MSB (D7)
is the watchdog bit and in some cases a register address bit;
the next three bits, D6 : D4, are used to select the command
register; and the remaining four bits, D3 : D0, are used to
configure and control the output and its protection features.
Multiple messages can be transmitted in succession to
accommodate those applications where daisy chaining is
desirable or to confirm transmitted data as long as the
messages are all multiples of eight bits. Any attempt made to
latch in a message that is not eight bits will be ignored.
The 33982B has defined registers, which are used to
configure the device and to control the state of the output.
Table 9, summarizes the SI registers. The registers are
addressed via D6 : D4 of the incoming SPI word (Table 8).
Table 8. SI Message Bit Assignment
Bit Sig SI Msg Bit
Message Bit Description
MSB
D7
Watchdog in: toggled to satisfy watchdog
requirements; also used as a register
address bit.
D6 : D4
D3 : D1
Register address bits.
Used to configure the inputs, outputs, and
the device protection features and SO
status content.
LSB
D0
Used to configure the inputs, outputs, and
the device protection features and SO
status content.
Analog Integrated Circuit Device Data
Freescale Semiconductor
33982
21