Intel® Quartus® Prime Pro Edition User Guide: Platform Designer

ID 683609
Date 10/04/2021
Public

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4.1.2. Designing Memory-Mapped Components

When designing with memory-mapped components, you can implement any component that contains multiple registers mapped to memory locations, for example, a set of four output registers to support software read back from logic. Components that implement read and write memory-mapped transactions require three main building blocks: an address decoder, a register file, and a read multiplexer.

The decoder enables the appropriate 32-bit or 64-bit register for writes. For reads, the address bits drive the multiplexer selection bits. The read signal registers the data from the multiplexer, adding a pipeline stage so that the component can achieve a higher clock frequency.

Figure 112. Control and Status Registers (CSR) in an Agent Component

This agent component has four write wait states and one read wait state. Alternatively, if you want high throughput, you may set both the read and write wait states to zero, and then specify a read latency of one, because the component also supports pipelined reads.