Re: [sv-ac] Hierarchical ref of local variable in action blocks

That was related to 3672: Hierarchical access to named block in assertion
action blocks

On Tue, Jul 19, 2011 at 12:02 PM, ben cohen <hdlcohen@gmail.com> wrote:

> Ran the following 3 models:
> From the current simulator that I have:
> 1) Action block local variable must be declared as "static" or "automatic"
> 2) If "static", then local var maintains its old value as expected.
> 3) assertion_label.var_name (e.g., *a1.x) does not work *
> *Ben *
> *-----------------------------------------*
> module asn;
> static int result, count=0;
> logic a=1, b=1, clk=1;
> initial forever #10 clk=!clk;
> * a1: assert property (@(posedge clk)a |-> ##3 b) begin *
> * static int x=0; x +=1; result = x; *
> end
> always @(posedge clk) begin
> count+=1;
> if(count>=6) begin
> b<=0;
> $display("count=%d, result=%d", count, result);
> end
> end
> endmodule
>
> # count= 6, result= 2
> # count= 7, result= 3
> # ** Error: Assertion error.
> # Time: 140 ns Started: 80 ns Scope: asn.a1 File: asn.sv Line: 18
> Expr: b
> # count= 8, result= 3
> # ** Error: Assertion error.
> # Time: 160 ns Started: 100 ns Scope: asn.a1 File: asn.sv Line: 18
> Expr: b
> # count= 9, result= 3
> # ** Error: Assertion error.
> # Time: 180 ns Started: 120 ns Scope: asn.a1 File: asn.sv Line: 18
> Expr: b
> # count= 10, result= 3
> # ** Error: Assertion error.
> # Time: 200 ns Started: 140 ns Scope: asn.a1 File: asn.sv Line: 18
> Expr: b
> ============================================================
> module asn_auto;
> static int result, count=0;
> logic a=1, b=1, clk=1;
> initial forever #10 clk=!clk;
> *a1: assert property (@(posedge clk)a |-> ##3 b) begin *
> * automatic int x=0; x +=1; result = x; *
> end
> always @(posedge clk) begin
> count+=1;
> if(count>=6) begin
> b<=0;
> $display("count=%d, result=%d", count, result);
> end
> end
> endmodule : asn_auto
> # count= 6, result= 1
> # count= 7, result= 1
> # ** Error: Assertion error.
> # Time: 140 ns Started: 80 ns Scope: asn_auto.a1 File: asn_auto.svLine: 18 Expr: b
> # count= 8, result= 1
> # ** Error: Assertion error.
> # Time: 160 ns Started: 100 ns Scope: asn_auto.a1 File: asn_auto.svLine: 18 Expr: b
> # count= 9, result= 1
> # ** Error: Assertion error.
> # Time: 180 ns Started: 120 ns Scope: asn_auto.a1 File: asn_auto.svLine: 18 Expr: b
> # count= 10, result= 1
> # ** Error: Assertion error.
> # Time: 200 ns Started: 140 ns Scope: asn_auto.a1 File: asn_auto.svLine: 18 Expr: b
>
> ==================================
> module asn_2;
> static int result, count=0, path_result;
> logic a=1, b=1, clk=1;
> initial forever #10 clk=!clk;
> a1: assert property (@(posedge clk)a |-> ##3 b) begin
> static int x=0; x +=1; result = x;
> end
> always @(posedge clk) begin
> count+=1;
> *path_result <= a1.x +1; // line 23*
> if(count>=6) begin
> b<=0;
> $display("count=%d, result=%d", count, result);
> $display("path_result=%d", path_result);
> end
> end
> endmodule
> *** Error: asn_2.sv(23): Unresolved reference to 'x'.*
>
>

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