add FIFO files

2019-11-20 21:09:14 +02:00
parent 9257364a38
commit 681d20fbf4
6 changed files with 187 additions and 1 deletions
@@ -0,0 +1,61 @@
+module status_signal(
+    output          fifo_full, 
+    output          fifo_empty, 
+    output          fifo_threshold, 
+    output          fifo_overflow, 
+    output          fifo_underflow, 
+    input           wr, 
+    input           rd, 
+    input           fifo_we, 
+    input           fifo_rd, 
+    input   [4:0]   wptr,
+    input   [4:0]   rptr,
+    input           clk,
+    input           rst_n);  
+ 
+    wire    fbit_comp, 
+            overflow_set, 
+            underflow_set;  
+    wire    pointer_equal;  
+    wire    [4:0]   pointer_result;  
+    reg     fifo_full, 
+            fifo_empty, 
+            fifo_threshold, 
+            fifo_overflow, 
+            fifo_underflow;  
+
+    assign fbit_comp = wptr[4] ^ rptr[4];  
+    assign pointer_equal = (wptr[3:0] - rptr[3:0]) ? 0:1;  
+    assign pointer_result = wptr[4:0] - rptr[4:0];  
+    assign overflow_set = fifo_full & wr;  
+    assign underflow_set = fifo_empty&rd; 
+
+    always @(*)  
+    begin  
+        fifo_full =fbit_comp & pointer_equal;  
+        fifo_empty = (~fbit_comp) & pointer_equal;  
+        fifo_threshold = (pointer_result[4]||pointer_result[3]) ? 1:0;  
+    end  
+
+    always @(posedge clk or negedge rst_n)  
+    begin  
+        if(~rst_n) fifo_overflow <=0;  
+        else if((overflow_set==1)&&(fifo_rd==0))  
+            fifo_overflow <=1;  
+        else if(fifo_rd)  
+            fifo_overflow <=0;  
+        else  
+            fifo_overflow <= fifo_overflow;  
+    end 
+
+    always @(posedge clk or negedge rst_n)  
+    begin  
+        if(~rst_n) fifo_underflow <=0;  
+        else if((underflow_set==1)&&(fifo_we==0))  
+            fifo_underflow <=1;  
+        else if(fifo_we)  
+            fifo_underflow <=0;  
+        else  
+            fifo_underflow <= fifo_underflow;  
+    end  
+endmodule