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Rewritten arst conditions in cdc_strobe.sv

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This commit is contained in:
Konstantin Pavlov 2021-12-15 11:17:10 +03:00
parent b91f6adac5
commit 36f89f2554
1 changed files with 11 additions and 8 deletions
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19
cdc_strobe.sv
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@ -35,7 +35,7 @@
/* --- INSTANTIATION TEMPLATE BEGIN --- /* --- INSTANTIATION TEMPLATE BEGIN ---
cdc_strobe_v2 cdc_wr_req ( cdc_strobe cdc_wr_req (
.arst( 1'b0 ), .arst( 1'b0 ),
.clk1( clk1 ), .clk1( clk1 ),
@ -77,19 +77,22 @@ module cdc_strobe (
// strb1 edge detector // strb1 edge detector
// prevents secondary strobe generation in case strb1 is not one-cycle-high // prevents secondary strobe generation in case strb1 is not one-cycle-high
logic strb1_ed; logic strb1_ed;
assign strb1_ed = (~strb1_b && strb1) && ~arst; assign strb1_ed = ( ~strb1_b && strb1 );
// 2 bit gray counter, it must NEVER be reset // 2 bit gray counter, it must NEVER be reset
logic [1:0] gc_FP_ATTR = '0; logic [1:0] gc_FP_ATTR = '0;
always @(posedge clk1) begin always @(posedge clk1 or posedge arst) begin
if( strb1_ed ) begin if( arst ) begin
gc_FP_ATTR[1:0] <= {gc_FP_ATTR[0],~gc_FP_ATTR[1]}; // incrementing counter // nop
end else begin
if( strb1_ed ) begin
gc_FP_ATTR[1:0] <= {gc_FP_ATTR[0],~gc_FP_ATTR[1]}; // incrementing counter
end
end end
end end
// buffering counter value on clk2 // buffering counter value on clk2
// gray counter does not need a synchronizer // gray counter doesnt need a synchronizer
logic [1:0][1:0] gc_b = '0; logic [1:0][1:0] gc_b = '0;
always @(posedge clk2 or posedge arst) begin always @(posedge clk2 or posedge arst) begin
if( arst ) begin if( arst ) begin
@ -102,7 +105,7 @@ module cdc_strobe (
end end
// gray_bit_b edge detector // gray_bit_b edge detector
assign strb2 = (gc_b[1][1:0] != gc_b[0][1:0] ) && ~arst; assign strb2 = ( gc_b[1][1:0] != gc_b[0][1:0] );
endmodule endmodule