Synchronize status signals for both clock domains in async frame FIFO

rtl/axis_async_frame_fifo.v

@@ -63,9 +63,12 @@ module axis_async_frame_fifo #
     /*
      * Status
      */
-    output wire                   overflow,
-    output wire                   bad_frame,
-    output wire                   good_frame
+    output wire                   input_status_overflow,
+    output wire                   input_status_bad_frame,
+    output wire                   input_status_good_frame,
+    output wire                   output_status_overflow,
+    output wire                   output_status_bad_frame,
+    output wire                   output_status_good_frame
 );
 
 reg [ADDR_WIDTH:0] wr_ptr = {ADDR_WIDTH+1{1'b0}}, wr_ptr_next;
@@ -91,6 +94,19 @@ reg overflow_reg = 1'b0;
 reg bad_frame_reg = 1'b0;
 reg good_frame_reg = 1'b0;
 
+reg overflow_sync1 = 1'b0;
+reg overflow_sync2 = 1'b0;
+reg overflow_sync3 = 1'b0;
+reg overflow_sync4 = 1'b0;
+reg bad_frame_sync1 = 1'b0;
+reg bad_frame_sync2 = 1'b0;
+reg bad_frame_sync3 = 1'b0;
+reg bad_frame_sync4 = 1'b0;
+reg good_frame_sync1 = 1'b0;
+reg good_frame_sync2 = 1'b0;
+reg good_frame_sync3 = 1'b0;
+reg good_frame_sync4 = 1'b0;
+
 reg [DATA_WIDTH+2-1:0] data_out_reg = {1'b0, {DATA_WIDTH{1'b0}}};
 
 //(* RAM_STYLE="BLOCK" *)
@@ -119,9 +135,13 @@ assign {output_axis_tlast, output_axis_tdata} = data_out_reg;
 assign input_axis_tready = (~full | DROP_WHEN_FULL) & ~input_rst_sync3;
 assign output_axis_tvalid = output_axis_tvalid_reg;
 
-assign overflow = overflow_reg;
-assign bad_frame = bad_frame_reg;
-assign good_frame = good_frame_reg;
+assign input_status_overflow = overflow_reg;
+assign input_status_bad_frame = bad_frame_reg;
+assign input_status_good_frame = good_frame_reg;
+
+assign output_status_overflow = overflow_sync3 ^ overflow_sync4;
+assign output_status_bad_frame = bad_frame_sync3 ^ bad_frame_sync4;
+assign output_status_good_frame = good_frame_sync3 ^ good_frame_sync4;
 
 // reset synchronization
 always @(posedge input_clk or posedge async_rst) begin
@@ -240,4 +260,38 @@ always @(posedge output_clk) begin
     end
 end
 
+// status synchronization
+always @(posedge input_clk) begin
+    if (input_rst_sync3) begin
+        overflow_sync1 <= 1'b0;
+        bad_frame_sync1 <= 1'b0;
+        good_frame_sync1 <= 1'b0;
+    end else begin
+        overflow_sync1 <= overflow_sync1 ^ overflow_reg;
+        bad_frame_sync1 <= bad_frame_sync1 ^ bad_frame_reg;
+        good_frame_sync1 <= good_frame_sync1 ^ good_frame_reg;
+    end
+end
+
+always @(posedge output_clk) begin
+    if (output_rst_sync3) begin
+        overflow_sync2 <= 1'b0;
+        overflow_sync3 <= 1'b0;
+        bad_frame_sync2 <= 1'b0;
+        bad_frame_sync3 <= 1'b0;
+        good_frame_sync2 <= 1'b0;
+        good_frame_sync3 <= 1'b0;
+    end else begin
+        overflow_sync2 <= overflow_sync1;
+        overflow_sync3 <= overflow_sync2;
+        overflow_sync4 <= overflow_sync3;
+        bad_frame_sync2 <= bad_frame_sync1;
+        bad_frame_sync3 <= bad_frame_sync2;
+        bad_frame_sync4 <= bad_frame_sync3;
+        good_frame_sync2 <= good_frame_sync1;
+        good_frame_sync3 <= good_frame_sync2;
+        good_frame_sync4 <= good_frame_sync3;
+    end
+end
+
 endmodule

rtl/axis_async_frame_fifo_64.v

@@ -66,9 +66,12 @@ module axis_async_frame_fifo_64 #
     /*
      * Status
      */
-    output wire                   overflow,
-    output wire                   bad_frame,
-    output wire                   good_frame
+    output wire                   input_status_overflow,
+    output wire                   input_status_bad_frame,
+    output wire                   input_status_good_frame,
+    output wire                   output_status_overflow,
+    output wire                   output_status_bad_frame,
+    output wire                   output_status_good_frame
 );
 
 reg [ADDR_WIDTH:0] wr_ptr = {ADDR_WIDTH+1{1'b0}}, wr_ptr_next;
@@ -94,6 +97,19 @@ reg overflow_reg = 1'b0;
 reg bad_frame_reg = 1'b0;
 reg good_frame_reg = 1'b0;
 
+reg overflow_sync1 = 1'b0;
+reg overflow_sync2 = 1'b0;
+reg overflow_sync3 = 1'b0;
+reg overflow_sync4 = 1'b0;
+reg bad_frame_sync1 = 1'b0;
+reg bad_frame_sync2 = 1'b0;
+reg bad_frame_sync3 = 1'b0;
+reg bad_frame_sync4 = 1'b0;
+reg good_frame_sync1 = 1'b0;
+reg good_frame_sync2 = 1'b0;
+reg good_frame_sync3 = 1'b0;
+reg good_frame_sync4 = 1'b0;
+
 reg [DATA_WIDTH+KEEP_WIDTH+2-1:0] data_out_reg = {1'b0, {KEEP_WIDTH{1'b0}}, {DATA_WIDTH{1'b0}}};
 
 //(* RAM_STYLE="BLOCK" *)
@@ -122,9 +138,13 @@ assign {output_axis_tlast, output_axis_tkeep, output_axis_tdata} = data_out_reg;
 assign input_axis_tready = (~full | DROP_WHEN_FULL) & ~input_rst_sync3;
 assign output_axis_tvalid = output_axis_tvalid_reg;
 
-assign overflow = overflow_reg;
-assign bad_frame = bad_frame_reg;
-assign good_frame = good_frame_reg;
+assign input_status_overflow = overflow_reg;
+assign input_status_bad_frame = bad_frame_reg;
+assign input_status_good_frame = good_frame_reg;
+
+assign output_status_overflow = overflow_sync3 ^ overflow_sync4;
+assign output_status_bad_frame = bad_frame_sync3 ^ bad_frame_sync4;
+assign output_status_good_frame = good_frame_sync3 ^ good_frame_sync4;
 
 // reset synchronization
 always @(posedge input_clk or posedge async_rst) begin
@@ -243,4 +263,38 @@ always @(posedge output_clk) begin
     end
 end
 
+// status synchronization
+always @(posedge input_clk) begin
+    if (input_rst_sync3) begin
+        overflow_sync1 <= 1'b0;
+        bad_frame_sync1 <= 1'b0;
+        good_frame_sync1 <= 1'b0;
+    end else begin
+        overflow_sync1 <= overflow_sync1 ^ overflow_reg;
+        bad_frame_sync1 <= bad_frame_sync1 ^ bad_frame_reg;
+        good_frame_sync1 <= good_frame_sync1 ^ good_frame_reg;
+    end
+end
+
+always @(posedge output_clk) begin
+    if (output_rst_sync3) begin
+        overflow_sync2 <= 1'b0;
+        overflow_sync3 <= 1'b0;
+        bad_frame_sync2 <= 1'b0;
+        bad_frame_sync3 <= 1'b0;
+        good_frame_sync2 <= 1'b0;
+        good_frame_sync3 <= 1'b0;
+    end else begin
+        overflow_sync2 <= overflow_sync1;
+        overflow_sync3 <= overflow_sync2;
+        overflow_sync4 <= overflow_sync3;
+        bad_frame_sync2 <= bad_frame_sync1;
+        bad_frame_sync3 <= bad_frame_sync2;
+        bad_frame_sync4 <= bad_frame_sync3;
+        good_frame_sync2 <= good_frame_sync1;
+        good_frame_sync3 <= good_frame_sync2;
+        good_frame_sync4 <= good_frame_sync3;
+    end
+end
+
 endmodule

tb/test_axis_async_frame_fifo.py

@@ -60,9 +60,12 @@ def dut_axis_async_frame_fifo(async_rst,
                  output_axis_tready,
                  output_axis_tlast,
 
-                 overflow,
-                 bad_frame,
-                 good_frame):
+                 input_status_overflow,
+                 input_status_bad_frame,
+                 input_status_good_frame,
+                 output_status_overflow,
+                 output_status_bad_frame,
+                 output_status_good_frame):
 
     if os.system(build_cmd):
         raise Exception("Error running build command")
@@ -83,9 +86,12 @@ def dut_axis_async_frame_fifo(async_rst,
                 output_axis_tready=output_axis_tready,
                 output_axis_tlast=output_axis_tlast,
 
-                overflow=overflow,
-                bad_frame=bad_frame,
-                good_frame=good_frame)
+                input_status_overflow=input_status_overflow,
+                input_status_bad_frame=input_status_bad_frame,
+                input_status_good_frame=input_status_good_frame,
+                output_status_overflow=output_status_overflow,
+                output_status_bad_frame=output_status_bad_frame,
+                output_status_good_frame=output_status_good_frame)
 
 def bench():
 
@@ -106,9 +112,12 @@ def bench():
     output_axis_tdata = Signal(intbv(0)[8:])
     output_axis_tvalid = Signal(bool(0))
     output_axis_tlast = Signal(bool(0))
-    overflow = Signal(bool(0))
-    bad_frame = Signal(bool(0))
-    good_frame = Signal(bool(0))
+    input_status_overflow = Signal(bool(0))
+    input_status_bad_frame = Signal(bool(0))
+    input_status_good_frame = Signal(bool(0))
+    output_status_overflow = Signal(bool(0))
+    output_status_bad_frame = Signal(bool(0))
+    output_status_good_frame = Signal(bool(0))
 
     # sources and sinks
     source_queue = Queue()
@@ -154,9 +163,12 @@ def bench():
                        output_axis_tready,
                        output_axis_tlast,
 
-                       overflow,
-                       bad_frame,
-                       good_frame)
+                       input_status_overflow,
+                       input_status_bad_frame,
+                       input_status_good_frame,
+                       output_status_overflow,
+                       output_status_bad_frame,
+                       output_status_good_frame)
 
     @always(delay(4))
     def input_clkgen():
@@ -166,18 +178,30 @@ def bench():
     def output_clkgen():
         output_clk.next = not output_clk
 
-    overflow_asserted = Signal(bool(0))
-    bad_frame_asserted = Signal(bool(0))
-    good_frame_asserted = Signal(bool(0))
+    input_status_overflow_asserted = Signal(bool(0))
+    input_status_bad_frame_asserted = Signal(bool(0))
+    input_status_good_frame_asserted = Signal(bool(0))
+    output_status_overflow_asserted = Signal(bool(0))
+    output_status_bad_frame_asserted = Signal(bool(0))
+    output_status_good_frame_asserted = Signal(bool(0))
 
     @always(input_clk.posedge)
-    def monitor():
-        if (overflow):
-            overflow_asserted.next = 1
-        if (bad_frame):
-            bad_frame_asserted.next = 1
-        if (good_frame):
-            good_frame_asserted.next = 1
+    def monitor_1():
+        if (input_status_overflow):
+            input_status_overflow_asserted.next = 1
+        if (input_status_bad_frame):
+            input_status_bad_frame_asserted.next = 1
+        if (input_status_good_frame):
+            input_status_good_frame_asserted.next = 1
+
+    @always(output_clk.posedge)
+    def monitor_2():
+        if (output_status_overflow):
+            output_status_overflow_asserted.next = 1
+        if (output_status_bad_frame):
+            output_status_bad_frame_asserted.next = 1
+        if (output_status_good_frame):
+            output_status_good_frame_asserted.next = 1
 
     @instance
     def check():
@@ -203,9 +227,12 @@ def bench():
                                             b'\x80\x00' +
                                             b'\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10')
 
-        overflow_asserted.next = 0
-        bad_frame_asserted.next = 0
-        good_frame_asserted.next = 0
+        input_status_overflow_asserted.next = 0
+        input_status_bad_frame_asserted.next = 0
+        input_status_good_frame_asserted.next = 0
+        output_status_overflow_asserted.next = 0
+        output_status_bad_frame_asserted.next = 0
+        output_status_good_frame_asserted.next = 0
 
         source_queue.put(test_frame)
         yield input_clk.posedge
@@ -220,9 +247,12 @@ def bench():
 
         assert rx_frame == test_frame
 
-        assert not overflow_asserted
-        assert not bad_frame_asserted
-        assert good_frame_asserted
+        assert not input_status_overflow_asserted
+        assert not input_status_bad_frame_asserted
+        assert input_status_good_frame_asserted
+        assert not output_status_overflow_asserted
+        assert not output_status_bad_frame_asserted
+        assert output_status_good_frame_asserted
 
         yield delay(100)
 
@@ -235,9 +265,12 @@ def bench():
                                             b'\x80\x00' +
                                             bytearray(range(256)))
 
-        overflow_asserted.next = 0
-        bad_frame_asserted.next = 0
-        good_frame_asserted.next = 0
+        input_status_overflow_asserted.next = 0
+        input_status_bad_frame_asserted.next = 0
+        input_status_good_frame_asserted.next = 0
+        output_status_overflow_asserted.next = 0
+        output_status_bad_frame_asserted.next = 0
+        output_status_good_frame_asserted.next = 0
 
         source_queue.put(test_frame)
         yield input_clk.posedge
@@ -252,9 +285,12 @@ def bench():
 
         assert rx_frame == test_frame
 
-        assert not overflow_asserted
-        assert not bad_frame_asserted
-        assert good_frame_asserted
+        assert not input_status_overflow_asserted
+        assert not input_status_bad_frame_asserted
+        assert input_status_good_frame_asserted
+        assert not output_status_overflow_asserted
+        assert not output_status_bad_frame_asserted
+        assert output_status_good_frame_asserted
 
         yield input_clk.posedge
         print("test 3: test packet with pauses")
@@ -265,9 +301,12 @@ def bench():
                                             b'\x80\x00' +
                                             b'\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10')
 
-        overflow_asserted.next = 0
-        bad_frame_asserted.next = 0
-        good_frame_asserted.next = 0
+        input_status_overflow_asserted.next = 0
+        input_status_bad_frame_asserted.next = 0
+        input_status_good_frame_asserted.next = 0
+        output_status_overflow_asserted.next = 0
+        output_status_bad_frame_asserted.next = 0
+        output_status_good_frame_asserted.next = 0
 
         source_queue.put(test_frame)
         yield input_clk.posedge
@@ -296,9 +335,12 @@ def bench():
 
         assert rx_frame == test_frame
 
-        assert not overflow_asserted
-        assert not bad_frame_asserted
-        assert good_frame_asserted
+        assert not input_status_overflow_asserted
+        assert not input_status_bad_frame_asserted
+        assert input_status_good_frame_asserted
+        assert not output_status_overflow_asserted
+        assert not output_status_bad_frame_asserted
+        assert output_status_good_frame_asserted
 
         yield delay(100)
 
@@ -315,9 +357,12 @@ def bench():
                                              b'\x80\x00' +
                                              b'\x02\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10')
 
-        overflow_asserted.next = 0
-        bad_frame_asserted.next = 0
-        good_frame_asserted.next = 0
+        input_status_overflow_asserted.next = 0
+        input_status_bad_frame_asserted.next = 0
+        input_status_good_frame_asserted.next = 0
+        output_status_overflow_asserted.next = 0
+        output_status_bad_frame_asserted.next = 0
+        output_status_good_frame_asserted.next = 0
 
         source_queue.put(test_frame1)
         source_queue.put(test_frame2)
@@ -341,9 +386,12 @@ def bench():
 
         assert rx_frame == test_frame2
 
-        assert not overflow_asserted
-        assert not bad_frame_asserted
-        assert good_frame_asserted
+        assert not input_status_overflow_asserted
+        assert not input_status_bad_frame_asserted
+        assert input_status_good_frame_asserted
+        assert not output_status_overflow_asserted
+        assert not output_status_bad_frame_asserted
+        assert output_status_good_frame_asserted
 
         yield delay(100)
 
@@ -360,9 +408,12 @@ def bench():
                                              b'\x80\x00' +
                                              b'\x02\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10')
 
-        overflow_asserted.next = 0
-        bad_frame_asserted.next = 0
-        good_frame_asserted.next = 0
+        input_status_overflow_asserted.next = 0
+        input_status_bad_frame_asserted.next = 0
+        input_status_good_frame_asserted.next = 0
+        output_status_overflow_asserted.next = 0
+        output_status_bad_frame_asserted.next = 0
+        output_status_good_frame_asserted.next = 0
 
         source_queue.put(test_frame1)
         source_queue.put(test_frame2)
@@ -395,9 +446,12 @@ def bench():
 
         assert rx_frame == test_frame2
 
-        assert not overflow_asserted
-        assert not bad_frame_asserted
-        assert good_frame_asserted
+        assert not input_status_overflow_asserted
+        assert not input_status_bad_frame_asserted
+        assert input_status_good_frame_asserted
+        assert not output_status_overflow_asserted
+        assert not output_status_bad_frame_asserted
+        assert output_status_good_frame_asserted
 
         yield delay(100)
 
@@ -414,9 +468,12 @@ def bench():
                                              b'\x80\x00' +
                                              b'\x02\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10')
 
-        overflow_asserted.next = 0
-        bad_frame_asserted.next = 0
-        good_frame_asserted.next = 0
+        input_status_overflow_asserted.next = 0
+        input_status_bad_frame_asserted.next = 0
+        input_status_good_frame_asserted.next = 0
+        output_status_overflow_asserted.next = 0
+        output_status_bad_frame_asserted.next = 0
+        output_status_good_frame_asserted.next = 0
 
         source_queue.put(test_frame1)
         source_queue.put(test_frame2)
@@ -445,9 +502,12 @@ def bench():
 
         assert rx_frame == test_frame2
 
-        assert not overflow_asserted
-        assert not bad_frame_asserted
-        assert good_frame_asserted
+        assert not input_status_overflow_asserted
+        assert not input_status_bad_frame_asserted
+        assert input_status_good_frame_asserted
+        assert not output_status_overflow_asserted
+        assert not output_status_bad_frame_asserted
+        assert output_status_good_frame_asserted
 
         yield delay(100)
 
@@ -461,9 +521,12 @@ def bench():
                                             b'\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10')
         test_frame.user = 1
 
-        overflow_asserted.next = 0
-        bad_frame_asserted.next = 0
-        good_frame_asserted.next = 0
+        input_status_overflow_asserted.next = 0
+        input_status_bad_frame_asserted.next = 0
+        input_status_good_frame_asserted.next = 0
+        output_status_overflow_asserted.next = 0
+        output_status_bad_frame_asserted.next = 0
+        output_status_good_frame_asserted.next = 0
 
         source_queue.put(test_frame)
         yield input_clk.posedge
@@ -472,9 +535,12 @@ def bench():
 
         assert sink_queue.empty()
 
-        assert not overflow_asserted
-        assert bad_frame_asserted
-        assert not good_frame_asserted
+        assert not input_status_overflow_asserted
+        assert input_status_bad_frame_asserted
+        assert not input_status_good_frame_asserted
+        assert not output_status_overflow_asserted
+        assert output_status_bad_frame_asserted
+        assert not output_status_good_frame_asserted
 
         yield delay(100)
 
@@ -487,9 +553,12 @@ def bench():
                                             b'\x80\x00' +
                                             bytearray(range(256))*2)
 
-        overflow_asserted.next = 0
-        bad_frame_asserted.next = 0
-        good_frame_asserted.next = 0
+        input_status_overflow_asserted.next = 0
+        input_status_bad_frame_asserted.next = 0
+        input_status_good_frame_asserted.next = 0
+        output_status_overflow_asserted.next = 0
+        output_status_bad_frame_asserted.next = 0
+        output_status_good_frame_asserted.next = 0
 
         source_queue.put(test_frame)
         yield input_clk.posedge
@@ -498,9 +567,12 @@ def bench():
 
         assert sink_queue.empty()
 
-        assert overflow_asserted
-        assert not bad_frame_asserted
-        assert not good_frame_asserted
+        assert input_status_overflow_asserted
+        assert not input_status_bad_frame_asserted
+        assert not input_status_good_frame_asserted
+        assert output_status_overflow_asserted
+        assert not output_status_bad_frame_asserted
+        assert not output_status_good_frame_asserted
 
         yield delay(100)
 
@@ -561,7 +633,7 @@ def bench():
 
         raise StopSimulation
 
-    return dut, monitor, source, sink, input_clkgen, output_clkgen, check
+    return dut, monitor_1, monitor_2, source, sink, input_clkgen, output_clkgen, check
 
 def test_bench():
     os.chdir(os.path.dirname(os.path.abspath(__file__)))

tb/test_axis_async_frame_fifo.v

@@ -45,9 +45,12 @@ wire input_axis_tready;
 wire [7:0] output_axis_tdata;
 wire output_axis_tvalid;
 wire output_axis_tlast;
-wire overflow;
-wire bad_frame;
-wire good_frame;
+wire input_status_overflow;
+wire input_status_bad_frame;
+wire input_status_good_frame;
+wire output_status_overflow;
+wire output_status_bad_frame;
+wire output_status_good_frame;
 
 initial begin
     // myhdl integration
@@ -64,9 +67,12 @@ initial begin
               output_axis_tdata,
               output_axis_tvalid,
               output_axis_tlast,
-              overflow,
-              bad_frame,
-              good_frame);
+              input_status_overflow,
+              input_status_bad_frame,
+              input_status_good_frame,
+              output_status_overflow,
+              output_status_bad_frame,
+              output_status_good_frame);
 
     // dump file
     $dumpfile("test_axis_async_frame_fifo.lxt");
@@ -95,9 +101,12 @@ UUT (
     .output_axis_tready(output_axis_tready),
     .output_axis_tlast(output_axis_tlast),
     // Status
-    .overflow(overflow),
-    .bad_frame(bad_frame),
-    .good_frame(good_frame)
+    .input_status_overflow(input_status_overflow),
+    .input_status_bad_frame(input_status_bad_frame),
+    .input_status_good_frame(input_status_good_frame),
+    .output_status_overflow(output_status_overflow),
+    .output_status_bad_frame(output_status_bad_frame),
+    .output_status_good_frame(output_status_good_frame)
 );
 
 endmodule

tb/test_axis_async_frame_fifo_64.py

@@ -62,9 +62,12 @@ def dut_axis_async_frame_fifo_64(async_rst,
                  output_axis_tready,
                  output_axis_tlast,
 
-                 overflow,
-                 bad_frame,
-                 good_frame):
+                 input_status_overflow,
+                 input_status_bad_frame,
+                 input_status_good_frame,
+                 output_status_overflow,
+                 output_status_bad_frame,
+                 output_status_good_frame):
 
     if os.system(build_cmd):
         raise Exception("Error running build command")
@@ -87,9 +90,12 @@ def dut_axis_async_frame_fifo_64(async_rst,
                 output_axis_tready=output_axis_tready,
                 output_axis_tlast=output_axis_tlast,
 
-                overflow=overflow,
-                bad_frame=bad_frame,
-                good_frame=good_frame)
+                input_status_overflow=input_status_overflow,
+                input_status_bad_frame=input_status_bad_frame,
+                input_status_good_frame=input_status_good_frame,
+                output_status_overflow=output_status_overflow,
+                output_status_bad_frame=output_status_bad_frame,
+                output_status_good_frame=output_status_good_frame)
 
 def bench():
 
@@ -112,9 +118,12 @@ def bench():
     output_axis_tkeep = Signal(intbv(0)[8:])
     output_axis_tvalid = Signal(bool(0))
     output_axis_tlast = Signal(bool(0))
-    overflow = Signal(bool(0))
-    bad_frame = Signal(bool(0))
-    good_frame = Signal(bool(0))
+    input_status_overflow = Signal(bool(0))
+    input_status_bad_frame = Signal(bool(0))
+    input_status_good_frame = Signal(bool(0))
+    output_status_overflow = Signal(bool(0))
+    output_status_bad_frame = Signal(bool(0))
+    output_status_good_frame = Signal(bool(0))
 
     # sources and sinks
     source_queue = Queue()
@@ -164,9 +173,12 @@ def bench():
                        output_axis_tready,
                        output_axis_tlast,
 
-                       overflow,
-                       bad_frame,
-                       good_frame)
+                       input_status_overflow,
+                       input_status_bad_frame,
+                       input_status_good_frame,
+                       output_status_overflow,
+                       output_status_bad_frame,
+                       output_status_good_frame)
 
     @always(delay(4))
     def input_clkgen():
@@ -176,18 +188,30 @@ def bench():
     def output_clkgen():
         output_clk.next = not output_clk
 
-    overflow_asserted = Signal(bool(0))
-    bad_frame_asserted = Signal(bool(0))
-    good_frame_asserted = Signal(bool(0))
+    input_status_overflow_asserted = Signal(bool(0))
+    input_status_bad_frame_asserted = Signal(bool(0))
+    input_status_good_frame_asserted = Signal(bool(0))
+    output_status_overflow_asserted = Signal(bool(0))
+    output_status_bad_frame_asserted = Signal(bool(0))
+    output_status_good_frame_asserted = Signal(bool(0))
 
     @always(input_clk.posedge)
-    def monitor():
-        if (overflow):
-            overflow_asserted.next = 1
-        if (bad_frame):
-            bad_frame_asserted.next = 1
-        if (good_frame):
-            good_frame_asserted.next = 1
+    def monitor_1():
+        if (input_status_overflow):
+            input_status_overflow_asserted.next = 1
+        if (input_status_bad_frame):
+            input_status_bad_frame_asserted.next = 1
+        if (input_status_good_frame):
+            input_status_good_frame_asserted.next = 1
+
+    @always(output_clk.posedge)
+    def monitor_2():
+        if (output_status_overflow):
+            output_status_overflow_asserted.next = 1
+        if (output_status_bad_frame):
+            output_status_bad_frame_asserted.next = 1
+        if (output_status_good_frame):
+            output_status_good_frame_asserted.next = 1
 
     @instance
     def check():
@@ -213,9 +237,12 @@ def bench():
                                             b'\x80\x00' +
                                             b'\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10')
 
-        overflow_asserted.next = 0
-        bad_frame_asserted.next = 0
-        good_frame_asserted.next = 0
+        input_status_overflow_asserted.next = 0
+        input_status_bad_frame_asserted.next = 0
+        input_status_good_frame_asserted.next = 0
+        output_status_overflow_asserted.next = 0
+        output_status_bad_frame_asserted.next = 0
+        output_status_good_frame_asserted.next = 0
 
         source_queue.put(test_frame)
         yield input_clk.posedge
@@ -230,9 +257,12 @@ def bench():
 
         assert rx_frame == test_frame
 
-        assert not overflow_asserted
-        assert not bad_frame_asserted
-        assert good_frame_asserted
+        assert not input_status_overflow_asserted
+        assert not input_status_bad_frame_asserted
+        assert input_status_good_frame_asserted
+        assert not output_status_overflow_asserted
+        assert not output_status_bad_frame_asserted
+        assert output_status_good_frame_asserted
 
         yield delay(100)
 
@@ -245,9 +275,12 @@ def bench():
                                             b'\x80\x00' +
                                             bytearray(range(256)))
 
-        overflow_asserted.next = 0
-        bad_frame_asserted.next = 0
-        good_frame_asserted.next = 0
+        input_status_overflow_asserted.next = 0
+        input_status_bad_frame_asserted.next = 0
+        input_status_good_frame_asserted.next = 0
+        output_status_overflow_asserted.next = 0
+        output_status_bad_frame_asserted.next = 0
+        output_status_good_frame_asserted.next = 0
 
         source_queue.put(test_frame)
         yield input_clk.posedge
@@ -262,9 +295,12 @@ def bench():
 
         assert rx_frame == test_frame
 
-        assert not overflow_asserted
-        assert not bad_frame_asserted
-        assert good_frame_asserted
+        assert not input_status_overflow_asserted
+        assert not input_status_bad_frame_asserted
+        assert input_status_good_frame_asserted
+        assert not output_status_overflow_asserted
+        assert not output_status_bad_frame_asserted
+        assert output_status_good_frame_asserted
 
         yield input_clk.posedge
         print("test 3: test packet with pauses")
@@ -275,9 +311,12 @@ def bench():
                                             b'\x80\x00' +
                                             bytearray(range(256)))
 
-        overflow_asserted.next = 0
-        bad_frame_asserted.next = 0
-        good_frame_asserted.next = 0
+        input_status_overflow_asserted.next = 0
+        input_status_bad_frame_asserted.next = 0
+        input_status_good_frame_asserted.next = 0
+        output_status_overflow_asserted.next = 0
+        output_status_bad_frame_asserted.next = 0
+        output_status_good_frame_asserted.next = 0
 
         source_queue.put(test_frame)
         yield input_clk.posedge
@@ -306,9 +345,12 @@ def bench():
 
         assert rx_frame == test_frame
 
-        assert not overflow_asserted
-        assert not bad_frame_asserted
-        assert good_frame_asserted
+        assert not input_status_overflow_asserted
+        assert not input_status_bad_frame_asserted
+        assert input_status_good_frame_asserted
+        assert not output_status_overflow_asserted
+        assert not output_status_bad_frame_asserted
+        assert output_status_good_frame_asserted
 
         yield delay(100)
 
@@ -325,9 +367,12 @@ def bench():
                                              b'\x80\x00' +
                                              b'\x02\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10')
 
-        overflow_asserted.next = 0
-        bad_frame_asserted.next = 0
-        good_frame_asserted.next = 0
+        input_status_overflow_asserted.next = 0
+        input_status_bad_frame_asserted.next = 0
+        input_status_good_frame_asserted.next = 0
+        output_status_overflow_asserted.next = 0
+        output_status_bad_frame_asserted.next = 0
+        output_status_good_frame_asserted.next = 0
 
         source_queue.put(test_frame1)
         source_queue.put(test_frame2)
@@ -351,9 +396,12 @@ def bench():
 
         assert rx_frame == test_frame2
 
-        assert not overflow_asserted
-        assert not bad_frame_asserted
-        assert good_frame_asserted
+        assert not input_status_overflow_asserted
+        assert not input_status_bad_frame_asserted
+        assert input_status_good_frame_asserted
+        assert not output_status_overflow_asserted
+        assert not output_status_bad_frame_asserted
+        assert output_status_good_frame_asserted
 
         yield delay(100)
 
@@ -370,9 +418,12 @@ def bench():
                                              b'\x80\x00' +
                                              b'\x02\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10')
 
-        overflow_asserted.next = 0
-        bad_frame_asserted.next = 0
-        good_frame_asserted.next = 0
+        input_status_overflow_asserted.next = 0
+        input_status_bad_frame_asserted.next = 0
+        input_status_good_frame_asserted.next = 0
+        output_status_overflow_asserted.next = 0
+        output_status_bad_frame_asserted.next = 0
+        output_status_good_frame_asserted.next = 0
 
         source_queue.put(test_frame1)
         source_queue.put(test_frame2)
@@ -405,9 +456,12 @@ def bench():
 
         assert rx_frame == test_frame2
 
-        assert not overflow_asserted
-        assert not bad_frame_asserted
-        assert good_frame_asserted
+        assert not input_status_overflow_asserted
+        assert not input_status_bad_frame_asserted
+        assert input_status_good_frame_asserted
+        assert not output_status_overflow_asserted
+        assert not output_status_bad_frame_asserted
+        assert output_status_good_frame_asserted
 
         yield delay(100)
 
@@ -424,9 +478,12 @@ def bench():
                                              b'\x80\x00' +
                                              b'\x02\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10')
 
-        overflow_asserted.next = 0
-        bad_frame_asserted.next = 0
-        good_frame_asserted.next = 0
+        input_status_overflow_asserted.next = 0
+        input_status_bad_frame_asserted.next = 0
+        input_status_good_frame_asserted.next = 0
+        output_status_overflow_asserted.next = 0
+        output_status_bad_frame_asserted.next = 0
+        output_status_good_frame_asserted.next = 0
 
         source_queue.put(test_frame1)
         source_queue.put(test_frame2)
@@ -455,9 +512,12 @@ def bench():
 
         assert rx_frame == test_frame2
 
-        assert not overflow_asserted
-        assert not bad_frame_asserted
-        assert good_frame_asserted
+        assert not input_status_overflow_asserted
+        assert not input_status_bad_frame_asserted
+        assert input_status_good_frame_asserted
+        assert not output_status_overflow_asserted
+        assert not output_status_bad_frame_asserted
+        assert output_status_good_frame_asserted
 
         yield delay(100)
 
@@ -471,9 +531,12 @@ def bench():
                                             b'\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10')
         test_frame.user = 1
 
-        overflow_asserted.next = 0
-        bad_frame_asserted.next = 0
-        good_frame_asserted.next = 0
+        input_status_overflow_asserted.next = 0
+        input_status_bad_frame_asserted.next = 0
+        input_status_good_frame_asserted.next = 0
+        output_status_overflow_asserted.next = 0
+        output_status_bad_frame_asserted.next = 0
+        output_status_good_frame_asserted.next = 0
 
         source_queue.put(test_frame)
         yield input_clk.posedge
@@ -482,9 +545,12 @@ def bench():
 
         assert sink_queue.empty()
 
-        assert not overflow_asserted
-        assert bad_frame_asserted
-        assert not good_frame_asserted
+        assert not input_status_overflow_asserted
+        assert input_status_bad_frame_asserted
+        assert not input_status_good_frame_asserted
+        assert not output_status_overflow_asserted
+        assert output_status_bad_frame_asserted
+        assert not output_status_good_frame_asserted
 
         yield delay(100)
 
@@ -497,9 +563,12 @@ def bench():
                                             b'\x80\x00' +
                                             bytearray(range(256))*2)
 
-        overflow_asserted.next = 0
-        bad_frame_asserted.next = 0
-        good_frame_asserted.next = 0
+        input_status_overflow_asserted.next = 0
+        input_status_bad_frame_asserted.next = 0
+        input_status_good_frame_asserted.next = 0
+        output_status_overflow_asserted.next = 0
+        output_status_bad_frame_asserted.next = 0
+        output_status_good_frame_asserted.next = 0
 
         source_queue.put(test_frame)
         yield input_clk.posedge
@@ -508,9 +577,12 @@ def bench():
 
         assert sink_queue.empty()
 
-        assert overflow_asserted
-        assert not bad_frame_asserted
-        assert not good_frame_asserted
+        assert input_status_overflow_asserted
+        assert not input_status_bad_frame_asserted
+        assert not input_status_good_frame_asserted
+        assert output_status_overflow_asserted
+        assert not output_status_bad_frame_asserted
+        assert not output_status_good_frame_asserted
 
         yield delay(100)
 
@@ -571,7 +643,7 @@ def bench():
 
         raise StopSimulation
 
-    return dut, monitor, source, sink, input_clkgen, output_clkgen, check
+    return dut, monitor_1, monitor_2, source, sink, input_clkgen, output_clkgen, check
 
 def test_bench():
     os.chdir(os.path.dirname(os.path.abspath(__file__)))

tb/test_axis_async_frame_fifo_64.v

@@ -47,9 +47,12 @@ wire [63:0] output_axis_tdata;
 wire [7:0] output_axis_tkeep;
 wire output_axis_tvalid;
 wire output_axis_tlast;
-wire overflow;
-wire bad_frame;
-wire good_frame;
+wire input_status_overflow;
+wire input_status_bad_frame;
+wire input_status_good_frame;
+wire output_status_overflow;
+wire output_status_bad_frame;
+wire output_status_good_frame;
 
 initial begin
     // myhdl integration
@@ -68,9 +71,12 @@ initial begin
               output_axis_tkeep,
               output_axis_tvalid,
               output_axis_tlast,
-              overflow,
-              bad_frame,
-              good_frame);
+              input_status_overflow,
+              input_status_bad_frame,
+              input_status_good_frame,
+              output_status_overflow,
+              output_status_bad_frame,
+              output_status_good_frame);
 
     // dump file
     $dumpfile("test_axis_async_frame_fifo_64.lxt");
@@ -101,9 +107,12 @@ UUT (
     .output_axis_tready(output_axis_tready),
     .output_axis_tlast(output_axis_tlast),
     // Status
-    .overflow(overflow),
-    .bad_frame(bad_frame),
-    .good_frame(good_frame)
+    .input_status_overflow(input_status_overflow),
+    .input_status_bad_frame(input_status_bad_frame),
+    .input_status_good_frame(input_status_good_frame),
+    .output_status_overflow(output_status_overflow),
+    .output_status_bad_frame(output_status_bad_frame),
+    .output_status_good_frame(output_status_good_frame)
 );
 
 endmodule