Re: [sv-ec] multi drive of variable via virtual interface

I've took this case from OVM Xbus / UVM Ubus example - so I assume that
none of the tool fails with error in such case

DANiel

On 5/27/2011 8:26 PM, Gran, Alex wrote:
> Daniel,
> I believe this should be an error. Are you expecting something different? If so, how are you expecting sig_read to behave.
>
> This rule for Sec 6.5 should be in effect for this case.
>
> The precise rule is that it shall be an error to have multiple continuous assignments or a mixture of procedural
> and continuous assignments writing to any term in the expansion of a written longest static prefix of a
> variable (see 11.5.3 for the definition of a longest static prefix).
>
> ~Alex
>
>
>
> -----Original Message-----
> From: owner-sv-ec@eda.org [mailto:owner-sv-ec@eda.org] On Behalf Of Neil Korpusik
> Sent: Friday, May 27, 2011 11:08 AM
> To: SV_EC List
> Cc: danielm
> Subject: [sv-ec] multi drive of variable via virtual interface
>
> <forwarding email from Daniel Mlynek>
>
> -------- Original Message --------
> Date: Fri, 27 May 2011 09:08:22 +0200
> From: Daniel Mlynek<danielm@aldec.com>
> To: "sv-ec@eda.org"<sv-ec@eda.org>
> Subject: multi drive of variable via continous assignment and procedural assignment
> via virtual interface
>
>
> In below code varaible sig_read is driven by dut module output and it is
> also driven by NBA to virtual interface select.
> How should tool behave for such code.
> Detect multidrive and fail?
>
>
> CODE:
>
> interface iface;
> logic clk;
> logic sig_read;
> endinterface
>
> module dut(input clk,output reg xbus_read);
> initial xbus_read<=1'bz;
> always @(posedge clk)begin
> xbus_read<=1'bz;
> $display("2: xbus_read<=1'bz");
> end
> endmodule
>
> class C;
> virtual iface vi;
> function new(virtual iface i);
> vi=i;
> endfunction
> function drive;
> vi.sig_read<=1;* //procedural drive of sig_read*
> $display("1: vi.sig_read<=1");
> endfunction
> endclass
>
> module top;
> iface iface_i();
> dut uut(iface_i.clk,iface_i.sig_read);* //dut instantation - continous drive of sig_read*
> C c =new(iface_i);
> initial iface_i.clk=0;
> always #5 iface_i.clk = ~ iface_i.clk;
> initial begin
> $display("START");
> $monitor($time,">>>>", iface_i.sig_read);
> @(posedge iface_i.clk)
> c.drive();
> @(posedge iface_i.clk);
> #1;
> $display("END");
> assert(iface_i.sig_read)else $fatal("fatal error");
> $finish;
> end
>
> endmodule
>
>
>

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