Xilinx V2.1 manual Block Interface, Block Parameters Dialog Box, Xilinx Blocks, Basic Elements

Models: V2.1

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Figure 3-16: Register block parameters dialog box

Xilinx Blocks

Block Interface

The block has one input port for the data and an optional input reset port. The initial output value is specified by the user in the block parameters dialog box (below). Data presented at the input will appear at the output after one sample period. Upon reset, the register assumes the initial value specified in the parameters dialog box.

The Register block differs from the Xilinx Delay block by providing an optional reset port and a user specifiable initial value.

Block Parameters Dialog Box

The block parameters dialog box can be invoked by double-clicking the icon in your Simulink model.

Figure 3-16: Register block parameters dialog box

Parameters specific to the block are:

Initial Value: specifies the initial value in the register.

Quantization (of Initital Value): specifies desired quantization effect; one on Round or Truncate.

Overflow Effect (of Initital Value): specifies desired overflow effect; Wrap, Saturate, or Flag as Error.

Register Only Valid Data: when checked, only valid values are registered. Extra logic is added when this option is selected, thus decreasing system performance.

Use Reset Port: when checked, the optional reset port is activated.

Use Enable Port: when checked, the optional clock enable port is activated.

Other parameters used by this block are explained in the Common Parameters section of the previous chapter.

The Register block is implemented as a synthesizable VHDL module. It does not use a Xilinx LogiCORE.

Basic Elements

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Xilinx V2.1 manual Block Interface, Block Parameters Dialog Box, Xilinx Blocks, 16:Register block parameters dialog box