rtl: utils: add up_counter module

Signed-off-by: liangkangnan <liangkangnan@163.com>

rtl/utils/up_counter.sv

@@ -0,0 +1,51 @@
+ /*                                                                      
+ Copyright 2021 Blue Liang, liangkangnan@163.com
+                                                                         
+ Licensed under the Apache License, Version 2.0 (the "License");         
+ you may not use this file except in compliance with the License.        
+ You may obtain a copy of the License at                                 
+                                                                         
+     http://www.apache.org/licenses/LICENSE-2.0                          
+                                                                         
+ Unless required by applicable law or agreed to in writing, software    
+ distributed under the License is distributed on an "AS IS" BASIS,       
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and     
+ limitations under the License.                                          
+ */
+
+module up_counter #(
+    parameter int unsigned WIDTH = 4
+    )(
+    input  logic             clk_i,
+    input  logic             rst_ni,
+    input  logic             clear_i,   // 同步清零
+    input  logic             en_i,      // 使能，开始计数
+    output logic [WIDTH-1:0] q_o,       // 当前计数值
+    output logic             overflow_o // 溢出标志
+    );
+
+    logic [WIDTH:0] counter_d, counter_q;
+
+    assign overflow_o = counter_q[WIDTH];
+    assign q_o = counter_q[WIDTH-1:0];
+
+    always_comb begin
+        counter_d = counter_q;
+
+        if (clear_i) begin
+            counter_d = '0;
+        end else if (en_i) begin
+            counter_d = counter_q + 1'b1;
+        end
+    end
+
+    always_ff @(posedge clk_i or negedge rst_ni) begin
+        if (!rst_ni) begin
+           counter_q <= '0;
+        end else begin
+           counter_q <= counter_d;
+        end
+    end
+
+endmodule