nelsobe

Why does PLL define a COMPENSATION value when that is not used?

1

The techmapper for xc7 [https://github.com/SymbiFlow/symbiflow-arch-defs/blob/master/xc/xc7/techmap/cells_map.v](https://github.com/SymbiFlow/symbiflow-arch-defs/blob/master/xc/xc7/techmap/cells_map.v) defines a default value for COMPENSATION in the PLL advanced module even though it is never used. Should that be removed? Or, is the techmapper...

Missing INIT string data in FASM for selected BRAM sites

19

When generating a large memory in Verilog, in some cases, parts of the BRAM INIT information is missing when the .bit file is converted to FASM. Here is an example...

Symbiflow-classroom: Array Initializers Do Not Work

4

SYMBIFLOW-CLASSROOM-PROJECT Using original Yosys frontend. If SV code contains a legal array declaration and initialization like this: ``` // Lookup table for % 3 calculation. logic[1:0] modmem[8] = '{0, 1,...

Running Symbiflow-examples with surelog

8

@acomodi @mkurc-ant In a recent conversation @mithro suggested there was a way to run the symbiflow-examples toolchain using the surelog SystemVerilog front end. We are preparing to have students run...

Symbiflow-classroom: "Error declaring a variable inside an always_comb block"

4

SYMBIFLOW-CLASSROOM-PROJECT Using original Yosys frontend. The tools give compile errors when the integer is declared local to the always_comb body: ``` always_comb begin integer index; if (hcount < H_PIXELS &&...

Symbiflow-classroom: "Multiple include causes error"

3

SYMBIFLOW-CLASSROOM-PROJECT Using the include macro to include the same module more than once in a project (perhaps from different locations in the files) causes an error. While bad practice, this...

Symbiflow-classroom:Reset of BRAM Output Register

11

SYMBIFLOW-CLASSROOM-PROJECT Below is a snippet of code from a riscv design used in our junior level course. As can be seen, the reading from the BRAM includes a reset condition...

Symbiflow-classroom: Initialization of memories using $readmemh()

4

SYMBIFLOW-CLASSROOM-PROJECT Using Yosys front end. The following code does NOT initialize the memory: // Load the Instruction Memory if (TEXT_MEMORY_FILENAME == "") begin $display("**** Top-Level I/O System: No instruction memory...

Documentation: How to keep install instructions up to date?

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The last step of the installation is to install a set of tar files like this: ``` mkdir -p $INSTALL_DIR/xc7/install wget -qO- https://storage.googleapis.com/symbiflow-arch-defs/artifacts/prod/foss-fpga-tools/symbiflow-arch-defs/continuous/install/20220404-212755/symbiflow-arch-defs-install-afbfe04.tar.xz | tar -xJC $INSTALL_DIR/xc7/install wget -qO- https://storage.googleapis.com/symbiflow-arch-defs/artifacts/prod/foss-fpga-tools/symbiflow-arch-defs/continuous/install/20220404-212755/symbiflow-arch-defs-xc7a50t_test-afbfe04.tar.xz...

Question: Possible to test tools without .xdc file?

4

When a design won't go through the tools it would be nice to be able to narrow down the issue by only compiling the individual module with the problem and...