Xilinx Blocks
LogiCOREs, as well as signals and control circuits to drive the clock network. Consequently, most System Generator blocks do not provide an explicit enable port. There are two exceptions> the Register block and the Addressable Shift Register block, which fundamentally require a CE port in order to target a high performance hardware implementation.
Simulink Enabled Subsystems can be used to enable blocks and subsystems. In order to support System Generator’s bit and cycle true modeling in Simulink, it is required that the enable port on an enabled subsystem be driven by the Enable Adapter block, found in the Xilinx blockset’s MATLAB I/O library. An example of this requirement is shown in the figure below. This shows an address generation model for a
Figure
The following blocks cannot be placed in an enabled subsystem with System Generator v2.1. The blocks are: CIC, Convolutional Encoder, FIR, FFT, Gateway In, Gateway Out, RS Decoder, RS Encoder, and Viterbi Decoder.
Enable Adapter
When using an enabled subsystem that contains Xilinx blocks, the enable port must be driven by a Xilinx Enable Adapter block. This block is a required interface to any enabled subsystem that contains a System Generator block. The Enable Adapter block’s output port must drive the subsystem’s enable port.
Gateway In
The Xilinx Gateway In block is the input into the Xilinx FPGA part of your Simulink design. It converts Simulink double precision input to the System Generator fixed point type, and defines an input port for the top level of the HDL design generated by System Generator.
MATLAB I/O | 97 |