Parameter override is exactly the same as default value parameter assignement. Shalom ________________________________ From: Daniel Mlynek [mailto:daniel.mlynek@aldec.com] Sent: Tuesday, July 08, 2008 6:38 PM To: Bresticker, Shalom; 'Surya Pratik Saha' Cc: 'Banerjee, Ayan'; sv-bc@server.eda-stds.org Subject: RE: [sv-bc] Query about '1 worse case with parameter is like below '1 used on parameter assignment list - but it still should return all ones? module top; sub #('1) uut(); initial uut.r1='1; endmodule module sub; parameter [63:0] p1 = 0; reg [63:0] r1 = 0; initial begin #0 $display( "%b",p1); $display( "%b",r1); end endmodule ________________________________ From: owner-sv-bc@server.eda.org [mailto:owner-sv-bc@server.eda.org] On Behalf Of Bresticker, Shalom Sent: 8 lipca 2008 16:13 To: Surya Pratik Saha Cc: Banerjee, Ayan; sv-bc@server.eda-stds.org Subject: RE: [sv-bc] Query about '1 Hi, One can make a case for claiming that `1 should be evaluated as self-determined as a port connection, but not using your argument. It is true that simulators give port connection size mismatch warnings. But the LRM does not require them to do so. The LRM does explicitly say that port connections are modeled as continuous assignments (unless port collapsing is performed). In contrast to regular continuous assignments where size-mismatching is frequently deliberately done, it is relatively rarely deliberately done on port connections and thus more likely to be an error. Regards, Shalom ________________________________ From: Surya Pratik Saha [mailto:spsaha@cal.interrasystems.com] Sent: Tuesday, July 08, 2008 5:05 PM To: Bresticker, Shalom Cc: Banerjee, Ayan; sv-bc@eda-stds.org Subject: Re: [sv-bc] Query about '1 Hi Shalom, I have some comment on e.g. <1> answer. Conceptually your answer is correct. But the answer should be <c>. Because at the time of port connection, the actual expression should be evaluated in context insensitive manner. Consider the following e.g: module top; wire [2:0] x; test t(x); endmodule module test(i); input [3:0] i; endmodule All standard simulators gives port connection size mismatch warning as per LRM. If the port connection is simple continuous assignment then there is no need to give that warning. Considering that, if '1 is evaluated in context insensitive manner, then as per SV LRM, the value will simple one bit 1. Hence the answer should be <c>. Regards Surya -------- Original Message -------- Subject: Re:[sv-bc] Query about '1 From: Bresticker, Shalom <shalom.bresticker@intel.com> <mailto:shalom.bresticker@intel.com> To: Banerjee, Ayan <ayan_banerjee@mentor.com> <mailto:ayan_banerjee@mentor.com> , sv-bc@eda-stds.org Date: Tuesday, July 08, 2008 7:09:33 PM I think the answers should be: ________________________________ From: owner-sv-bc@server.eda.org [mailto:owner-sv-bc@server.eda.org] On Behalf Of Banerjee, Ayan Sent: Tuesday, July 08, 2008 3:57 PM To: sv-bc@server.eda-stds.org Subject: [sv-bc] Query about '1 Hi, I have 3 queries about what should be the correct behavior for the following 3 cases. 1) What should be behavior if '1 is passed to a port as is done in the following testcase? module top; bottom inst('1); endmodule module bottom(a); input [63:0] a; initial $display("%b", a); endmodule Should it be a) 1111111111111111111111111111111111111111111111111111111111111111 or b) zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz1 or c) 0000000000000000000000000000000000000000000000000000000000000001 [SB] a. This should be treated as the continuous assignment "bottom.a = '1" . 2) What should be the behavior if '1 is used as parameter value module top; parameter [63:0] p1 = '1; initial $display("%b",p1); endmodule Should it be a) 1111111111111111111111111111111111111111111111111111111111111111 or b) 0000000000000000000000000000000000000000000000000000000000000001 [SB] a. Treated as assignment "p1[63:0] = '1". 3) Similar to 2 but in a more general case what should be the value of parameter if range is specified which is more than 32 but the expression assigned is of 32 bit. Should the expression be evaluated in 32 bit or with the size of parameter? module top; parameter [63:0] p1 = 1'b1 << 63; initial $display("%b",p1); endmodule Should it be a) 0000000000000000000000000000000000000000000000000000000000000000 or b) 1000000000000000000000000000000000000000000000000000000000000000 The behavior of simulators are different in the above cases. Thanks in advance for your help. [SB] With the size of the parameter. The answer should be b. We discussed this in the past. Shalom -Regards, Ayan --------------------------------------------------------------------- Intel Israel (74) Limited This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). Any review or distribution by others is strictly prohibited. If you are not the intended recipient, please contact the sender and delete all copies. -- This message has been scanned for viruses and dangerous content by MailScanner <http://www.mailscanner.info/> , and is believed to be clean. --------------------------------------------------------------------- Intel Israel (74) Limited This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). Any review or distribution by others is strictly prohibited. If you are not the intended recipient, please contact the sender and delete all copies. -- This message has been scanned for viruses and dangerous content by MailScanner <http://www.mailscanner.info/> , and is believed to be clean. --------------------------------------------------------------------- Intel Israel (74) Limited This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). Any review or distribution by others is strictly prohibited. If you are not the intended recipient, please contact the sender and delete all copies. -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.Received on Tue Jul 8 12:02:36 2008
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