diff options
| author | Warrick Lo <wlo@warricklo.net> | 2026-07-07 06:01:17 +0000 |
|---|---|---|
| committer | Warrick Lo <wlo@warricklo.net> | 2026-07-07 06:01:17 +0000 |
| commit | 6c24f49f3239c79173fd180d065f8f03cfaeabfd (patch) | |
| tree | 4ac1ebc964784b655cda35de979331196b19a3c2 /verif/formal/simple_alu/simple_alu_fv.sv | |
| parent | Merge branch 'feature/fu' from MyDariell (diff) | |
| parent | Add DCO [skip ci] (diff) | |
| download | montreal-6c24f49f3239c79173fd180d065f8f03cfaeabfd.tar.xz montreal-6c24f49f3239c79173fd180d065f8f03cfaeabfd.zip | |
Sync with 'master'feature/fu
Signed-off-by: Warrick Lo <wlo@warricklo.net>
Diffstat (limited to 'verif/formal/simple_alu/simple_alu_fv.sv')
| -rw-r--r-- | verif/formal/simple_alu/simple_alu_fv.sv | 50 |
1 files changed, 0 insertions, 50 deletions
diff --git a/verif/formal/simple_alu/simple_alu_fv.sv b/verif/formal/simple_alu/simple_alu_fv.sv deleted file mode 100644 index 98c05a7..0000000 --- a/verif/formal/simple_alu/simple_alu_fv.sv +++ /dev/null @@ -1,50 +0,0 @@ -// Formal verification module for simple_alu. -// All ports are inputs - this module only observes DUT signals, never drives them. -// Instantiated via simple_alu_top_fv.sv wrapper (bind unsupported in open-source Yosys). -module simple_alu_fv ( - input logic clk_i, - input logic [31:0] a_i, - input logic [31:0] b_i, - input logic sel_i, - input logic rst_ni, - - input logic [31:0] y_i, - input logic overflow_i - ); - - // ------------------------------------------------------------------------- - // Initial assumptions - constrain starting state so solver doesn't - // explore garbage initial register values - // ------------------------------------------------------------------------- - initial assume (~rst_ni); - initial assume (y_i == '0); - initial assume (overflow_i == 1'b0); - - //assertion check: if rst deasserted, y tied to 0 - //assertions are what we want to prove, formal verification is the engine that proves it - // property p_rst_y; - // @(posedge clk_i) - // ~rst_ni |=> (y_i=='0); - // endproperty - // a_rst_y: assert property (p_rst_y) - // else $error("RESET CHECK FAILED: rst_ni=%0b y_i=%0h, expected y=0", rst_ni, y_i); - - // Reset check - y must be 0 one cycle after reset asserts (active low) - always @(posedge clk_i) begin - if ($past(~rst_ni)) begin - assert (y_i == '0); - assert (overflow_i == 0); - end - end - - // ------------------------------------------------------------------------- - // Cover statements - solver finds shortest path to reach each state - // These generate VCD traces you can inspect in GTKWave - // ------------------------------------------------------------------------- - - always @(posedge clk_i) begin - cover ($past(sel_i == 0) && overflow_i == 1'b1); // addition overflow - cover ($past(sel_i == 1) && overflow_i == 1'b1); // subtraction underflow - end - -endmodule |