33793 Datasheet, PDF (13/27 Pages) Freescale Semiconductor, Inc – Distributed System Interface (DSI) Sensor Interface

FUNCTIONAL DEVICE OPERATION
OPERATIONAL MODES
FUNCTIONAL DEVICE OPERATION
OPERATIONAL MODES
A device may be permanently programmed one time with
an address using a two-command sequence. The first step is
satisfied on the reception of an Initialization command with
address set to zero, the PA[3:0] set to the address to be
programmed, and the NV bit set. This will cause the address
contained in the PA[3:0] bits to be stored in the address
register and the bus switch closed. The second step is taken
when a Read/Write NVM command is received with the
PA[3:0] bits matching the A[3:0] bits and also matching the
bits stored in the 33793 address register. This will cause the
33793 to permanently store this address into an internal NVM
area.
Table 6. DSI Bus Commands
Command
C3 C2 C1 C0
Size
Description
0
0
0
0
LW Initialization
0
0
01
SW ^{Request Status}
0
0
10
SW ^{Request Value 0}
0
0
1
1
LW I/O Control
0
1
00
SW ^{Request ID Information}
0
1
01
SW ^{Request Value 1}
0
1
10
SW Request Value 2
0
1
11
SW ^Clear
1
0
00
SW ^{Request Value 3}
1
0
0
1
LW Read/Write NVM
1
0
1
0
Reserved
1
0
1
1
Reserved
1
1
00
SW Clear Logic Out
1
1
01
SW ^{Set Logic Out}
1
1
1
0
Reserved
1
1
1
1
LW Reverse Initialization
Legend
BS = Controls closing of the Bus Switch (1 = close).
DR[3:0] = Direction of I/O. 1 = Output.
G[1:0] = Group assignment (the 33793 does not use these bits).
L[3:0] = Level to output on I/O if configured as outputs.
MESSAGES
The messages follow the format defined in the Distributed
Systems Interface Specification rev 1.0 unless otherwise
noted.
DSI BUS COMMANDS
This device can recognize and respond to both long-word
and short-word commands. A command word summary is
shown in Table 6. SW in the “Size” column of the table
indicates short-word commands and LW indicates long-word
commands. Short-word commands may also be sent in the
long-word format. However, when these commands are sent
in the long-word format, it is recommended that the data byte
be sent as $00 to maintain future compatibility. All commands
marked reserved should not be sent to 33793 slaves.
Data
D7
D6 D5 D4
D3
D2
D1
D0
NV
BS G1 G0 PA3
PA2
PA1 PA0
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
L3
L2
L1 L0 DR3 DR2
DR1 DR0
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
1
1
1
1
PA3
PA2
PA1 PA0
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
NV
BS G1 G0 PA3
PA2
PA1 PA0
LO = Logic Out level.
PA[3:0] = Bus Address to set the device to.
NV = Allows nonvolatile address programming if set to "1".
Analog Integrated Circuit Device Data
Freescale Semiconductor
33793
13