Wrong parameter value assigned to PageAddrWidth of idma_legalizer_page_splitter in idma_legalizer.sv.tpl?

[Kevin99214]

I've been running into an issue synthesizing idma_legalizer_page_splitter in the block below. It is saying that i is out of range

  always_comb begin : proc_range_select
        page_offset = '0;
        for (int i = 0; i < PageAddrWidth; i++) begin
            page_offset[i] = page_addr_width > i ? addr_i[i] : 1'b0;
        end
    end

The discrepancy seems to be in idma_legalizer.sv.tpl. The instantiation of idma_legalizer_page_splitter has parameter PageAddrWidth set to PageSize, but it passes in page_addr_t which has a width of $clog2(PageSize).

idma_legalizer_page_splitter #(
      .OffsetWidth   ( OffsetWidth ),
      .PageAddrWidth ( PageSize    ),
      .addr_t        ( addr_t      ),
      .page_len_t    ( page_len_t  ),
      .page_addr_t   ( page_addr_t )
  )

Is this a typo or have I missed something?

[thommythomaso]

Can you please provide some more information about your setup? Which tool are you using to synthesize the hardware? What parameterization?

[Kevin99214]

Sorry, by synthesizing I meant a SynthesisError (from Spyglass Lint). This is the exact error from it.

0xEEB	SYNTH_5255		SynthesisError	external/opensrc-idma/src/backend/idma_legalizer_page_splitter.sv	53	1000	idma_legalizer_page_splitter -> Illegal bit select. Index 11 for "page_offset" is out of range [10:0] in expression: "page_offset[I]"

I am using the AXI version of the DMA, parameter values from the idma_legalizer_rw_axi are:

DataWidth = 64
AddrWidth = 56
StrbWidth = 8
OffsetWidth = 3
PageSize = 2048
PageAddrWidth = 11

In module declaration:
-> PageSize of 2048 gets passed to the parameter of PageAddrWidth
-> page_addr_t is typedef logic [PageAddrWidth-1:0]

In always_comb + for loop:
-> PageAddrWidth is 2048
-> page_offset is declared as page_addr_t (11 bit wide logic)

Not an urgent issue, just seeing if my lint cleanup is done correctly