33793 Datasheet, PDF (21/27 Pages) Freescale Semiconductor, Inc – Distributed System Interface (DSI) Sensor Interface

FUNCTIONAL DEVICE OPERATION
DSI COMMANDS AND RESPONSES
Table 27. Reverse Initialization Command Format
Legend
A[3:0] = Address bits. These bits are the slave address. For
programmable devices these bits are all set to zero. For pre-
programmed devices these bits contain the pre-programmed
address and must match the PA[3:0] bits.
NV = Nonvolatile Memory Write. When set to a one, this bit allows a
subsequent NVM command to store a nonvolatile address. When set to a
zero, NVM programming is disallowed. Once a permanent address has
been stored in the device, setting the NV bit to a one has no effect.
G[1:0] = Group bits. These bits are the group number for the slave. X[3:0] = Cyclic Redundancy Check (CRC). The CRC as calculated by the
These bits are not used by this device and should be set to “0”. master.
PA[3:0] = Program Address bits. These bits are the address that is
to be stored into the slave’s address register.
REVERSE INITIALIZATION RESPONSE
This response message is sent during the next message
following a valid Reverse Initialization command to the
addressed device. The response is shown in Table 28. Since
this is a long-word only command, the short-word response is
invalid. No response is generated if the command address
field was $0.
Table 28. Reverse Initialization Response Format
High Byte
Low Byte
CRC
A3 A2 A1 A0 0
0
0 BF NV BS G1 G0 PA3 PA2 PA1 PA0 X3 X2 X1 X0
Legend
A[3:0] = Address bits.The slave address.
NV = Nonvolatile Memory Write. The value of the NV bit in the slave.
BF = Bus Fault. BUSIN short to battery detected.
PA[3:0] = Bus Address to set the device to.
BS = Controls closing of the Bus Switch (1=close).
X[3:0] = Cyclic Redundancy Check (CRC). The CRC as calculated by the
G[1:0] = Group bits. Not used on this part, will be set to “0”. The ^slave.
group number programmed into the slave.
Analog Integrated Circuit Device Data
Freescale Semiconductor
33793
21