Chapter 2
Theory of Operation
2-26
©
National Instruments Corporation
Figure 2-19.
RTSI Bus Interface Circuitry Block Diagram
The RTSI functionality is provided in the DAQ-STC chip. This RTSI
trigger module consists of seven 12-to-1 multiplexers that drive seven RTSI
Trigger bus signals and four 8-to-1 multiplexers that drive the four RTSI
board signals.
Any of the seven RTSI trigger bus signals can be driven by eight internally
generated timing signals and the four RTSI board signals. Similarly, the
four RTSI board signals can be driven by any of the RTSI trigger bus
signals. Of the four RTSI board signals, only one is used. By programming
certain bits in the DAQ-STC, you can drive the CONVERT pulse onto
RTSI_BRD0 and then onto any of the TRIGGER lines.
RTSI Bus Connector
DAQ-STC
TRIG1
TRIG2
CONVERT*
UPDATE*
WFTRIG
GPCTR0_SOURCE
GPCTR0_GATE
GPCTR0_OUT
STARTSCAN
AIGATE
mux
SISOURCE
AOGATE
UISOURCE
AO2GATE
UI2SOURCE
GPCTR1_SOURCE
RTSI Switch
Trigger
7
Clock
GPCTR1_GATE
RTSI_OSC (20 MHz)