Fix reconvergence issue in synchronizer (#150)

bensampson5 · Feb 7, 2022 · 989a51a · 989a51a
1 parent 6e8d336
commit 989a51a
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Showing 2 changed files with 7 additions and 9 deletions.
diff --git a/libsv/synchronizers/synchronizer.sv b/libsv/synchronizers/synchronizer.sv
@@ -2,16 +2,15 @@
 `define LIBSV_SYNCHRONIZERS_SYNCHRONIZER
 
 module synchronizer #(
-    parameter int DATA_WIDTH  /* verilator public_flat_rd */ = 1,
-    parameter int FF_STAGES  /* verilator public_flat_rd */  = 2
+    parameter int FF_STAGES  /* verilator public_flat_rd */ = 2
 ) (
-    input  logic                  i_clock,
-    input  logic                  i_aresetn,
-    input  logic [DATA_WIDTH-1:0] i_data,
-    output logic [DATA_WIDTH-1:0] o_data
+    input  logic i_clock,
+    input  logic i_aresetn,
+    input  logic i_data,
+    output logic o_data
 );
 
-    logic [FF_STAGES-1:0][DATA_WIDTH-1:0] sync_mem;
+    logic [FF_STAGES-1:0] sync_mem;
 
     always_ff @(posedge i_clock, negedge i_aresetn) begin
         if (!i_aresetn) begin

diff --git a/tests/synchronizers/test_synchronizer.py b/tests/synchronizers/test_synchronizer.py
@@ -13,7 +13,6 @@ def test_synchonrizer(pytestconfig):
 async def cocotb_test_synchonrizer(dut):
     """Synchronizer test"""
 
-    data_width = int(dut.DATA_WIDTH)
     ff_stages = int(dut.FF_STAGES)
 
     cocotb.fork(Clock(dut.i_clock, 2).start())
@@ -22,7 +21,7 @@ async def cocotb_test_synchonrizer(dut):
     await FallingEdge(dut.i_clock)
     dut.i_aresetn.value = 1
 
-    sync_value = 1 % (2 ** data_width)
+    sync_value = 1
     dut.i_data.value = sync_value
     for _ in range(ff_stages):
         assert dut.o_data.value != sync_value