National Instruments 776570-00 - Digital Control Circuitry

Chapter 4 Theory of Operation
SCXI-1120/D User Manual 4-4 www.natinst.com
Digital Control Circuitry
Figure 4-3 diagrams the SCXI-1120/D digital control.
Figure 4-3.
SCXI-1120/D Digital Control
The digital control section consists of the Configuration Register and the
Module ID Register.
The Configuration Register provides channel selection and configures the
SCXI-1120/D for scanning options. All the control bits are fed into a latch
before being routed to the rest of the module. The channel-select bits are
taken directly from the shift register.
The Module ID Register contains the module ID 4 hex, a code unique to the
SCXI-1120, or 44 hex, a code unique to the SCXI-1120D. You can read this
module ID over the SCXIbus to determine the type of module in a
particular slot.
Module ID Register
Configuration
Register
Serial Data Out
Input Channel
Select
Output
Stage
Control
Hardware
Scan
Control
SCANCLK
Path
Control
Buffered
Serial Data In
Buffered Digital
Control Signals