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
SERDATIN
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
SERDATOUT
Parallel
Data
Output Mode
Control (Data
Routing)
Serial Data
Ouput Mode Select
Figure 3-3. Digital Interface and Routing Circuitry Block Diagram