Theory of Operation
Chapter 3
SCXI-1163 User Manual
3-4
© National Instruments Corporation
Table 3-1. SCXIbus Equivalents for Rear Signal Connector
Rear Signal Connector
Signal
SCXIbus Equivalent
SERDATIN
MOSI
DAQD*/A
D*/A
SLOT0SEL*
INTR*
SERCLK
SPICLK
SERDATOUT
MISO
When the primary mode of operation is jumper configured to serial mode, the SCXI-1163
module converts the data acquisition board signals to open-collector signals on the backplane of
the SCXI chassis. For the data acquisition board to talk to a slot, the board must first assert the
SS* for that slot. To do this, assert INTR* low, write a 16-bit number over MOSI corresponding
to the desired slot (and chassis if you are using an SCXI-1001 chassis), and release INTR* high.
At this point, the SS* of the desired slot is asserted low and the data acquisition board can
communicate with the module in that slot according to the SPI protocol.
Interface and Routing Circuitry
Figure 3-3 shows a diagram of the SCXI-1163 and SCXIbus digital interface circuitry.
RESET*
MISO
SPICLK
INTR*
D*/A
MOSI
SS*
SCXIbus
SERDA
TIN
DAQD*/A
SLOT0SEL
SERCLK
Primary Mode
Control (Rear
Connector Routing)
SCXI Digital
Interface
Buffered Digital
Signal Controls
Buffered
Serial Data
Address
Handler
and
Registers
Rear Connector
Optically Isolated Inputs
SERDA
T
OUT
Parallel
Data
Output Mode
Control (Data
Routing)
Serial Data
Ouput Mode Select
Figure 3-3. Digital Interface and Routing Circuitry Block Diagram