Placing a Crosspoint Switch Module
The configurable Crosspoint Switch module provides an efficient means by which to switch signals in a design. Figure 1 shows a simple example circuit using this instrument.
The circuitry in Figure 1 has been constructed to simplify illustration of how the device works. Inputs to the device are simply generated from a configurable Digital I/O module, and the outputs of the Crosspoint Switch module wired back as inputs to the same Digital I/O device. Typically, the output blocks of the instrument would be connected elsewhere in the design, for FPGA testing/debugging purposes.
In the example circuit above, the Crosspoint Switch module has been configured with two input blocks (AIN
, BIN
) and three output blocks (AOUT
, BOUT
, COUT
). The common block structure for these inputs and outputs has been defined with the following constituent signals:
Addr[15..0]
Data[15..0]
The generated 16-bit digital signals from the Digital I/O module are fed into the Crosspoint Switch module as follows:
- Output signals
X_Addr
andX_Data
are connected to theAddr
andData
signals of input blockAIN
, respectively.
- Output signals
Y_Addr
andY_Data
are connected to theAddr
andData
signals of input blockBIN
, respectively.
The output blocks of the Crosspoint Switch module are connected back as input signals to the Digital I/O module as follows:
Addr
andData
signals of output blockAOUT
are connected to input signalsChannelA_Addr
andChannelA_Data
, respectively.
Addr
andData
signals of output blockBOUT
are connected to input signalsChannelB_Addr
andChannelB_Data
, respectively.
Addr
andData
signals of output blockCOUT
are connected to input signalsChannelC_Addr
andChannelC_Data
, respectively.
Remember that when using any virtual instrument in a design, you must ensure that the Soft Devices JTAG chain is enabled. For more information, see Enabling the Soft Devices JTAG Chain.