33793 Datasheet, PDF (18/27 Pages) Freescale Semiconductor, Inc – Distributed System Interface (DSI) Sensor Interface

FUNCTIONAL DEVICE OPERATION
DSI COMMANDS AND RESPONSES
Table 17. I/O Control Response Format
A3 A2 A1 A0 0 0 0 0 L3
Legend
A[3:0] = Address bits.
DR[3:0] = I/O enabled as outputs (1 = enabled as output).
L2 L1 L0 DR3 DR2 DR1 DR0 X3 X2 X1 X0
L[3:0] = Programmed values.
X[3:0] = Cyclic Redundancy Check (CRC). The CRC as calculated by the
slave.
REQUEST ID COMMAND
This command will cause the device ID information to be
read from internal storage and returned to the master during
the response to the next message. The command format is
found in Table 18.
Table 18. Request ID Command Format
Data
Address
Command
CRC
––––
–
–
–
– A3
Legend
A[3:0] = Address bits. The address of the selected device. An
address value of “0000” is ignored by all devices.
A2 A1 A0 0 1 0 0 X3 X2 X1 X0
X[3:0] = Cyclic Redundancy Check (CRC). The CRC as calculated by the
master.
REQUEST ID RESPONSE
This response message is sent during the next message
following a valid long-word Request ID command to the
addressed device. The response format is found in Table 19.
The high byte is omitted during the short-word response. No
response is generated if the command address field was $0.
Table 19. Request ID Response Format
Address
Status
Data
CRC
A3 A2 A1 A0 0 0 0 0 V2 V1 V0
0
0
0
1
1 X3 X2 X1 X0
Legend
A[3:0] = Address bits. The slave address.
X[3:0] = Cyclic Redundancy Check (CRC). The CRC as calculated by the
V[2:0] = Device version number. The silicon version number of the ^slave.
device. For this device the device type is 00011 as indicated by the
lowest bits.
CLEAR COMMAND
This command will open the bus switch and reset all
registers to the reset state. The command format is found in
Table 20. No response is generated for the Clear command.
Table 20. Clear Command Format
Data
Address
Command
CRC
––––
–
–
–
– A3
Legend
A[3:0] = Address bits. The address of the selected device. An
address value of “0000” clears all devices.
A2 A1 A0 0 1 1 1 X3 X2 X1 X0
X[3:0] = Cyclic Redundancy Check (CRC). The CRC as calculated by the
master.
READ/WRITE NVM COMMAND
If the NV bit has been set by a previous Initialization
command and the NVM has not been programmed
previously, this command will permanently program the
device’s one-time programmable address and return the
programmed value during the next message time. Once
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programmed, this nonvolatile address is used to set the
device address register on the next and all subsequent
power-ups. If the device is not blank, this command will return
the programmed value during the next message time.
Programming the NVM address to $0 is allowed. This
ensures that the device always acts as a dynamically
Analog Integrated Circuit Device Data
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