WB_ASP - Interfacing to External Memory

In a design that contains both software and hardware functions, certain variables may be common to the two. Such variables that need to be accessed by the software and hardware can be allocated in shared memory. This could be Block RAM within the FPGA itself, or external memory, such as SRAM. Both the host processor and WB_ASP must be wired to this shared memory.

Simply use the WB_ASP's external memory interface to connect to the required physical memory, as you would any other memory-based peripheral (such as a VGA Controller, or a BT656 Controller).

In terms of addressing, a software function can simply pass a pointer value – to a variable (data object) stored in the shared memory – as a parameter to a called hardware function.

For more information on memory, including use of shared memory, refer to Section 3.5 Memory and Memory Qualifiers, in the C-to-Hardware Compiler User Manual.