Hi, All - Two aggregate / struct questions below. Attached in a separate file is the following example: typedef struct { bit [3:0] dst_addr; bit [3:0] src_addr; bit [31:0] data; bit [7:0] crc; } pkt_s; module test; pkt_s pkt1; initial begin init('{4'h9, 4'h6, 32'h1234ABCD, 8'h00}); pkt1.crc = gen_crc(pkt1.data); show_pkt; $finish; end function void init (pkt_s d); pkt1 = d; endfunction function [7:0] gen_crc (int d); for (int i=0;i<8;i++) gen_crc[i]=^d[(i*4)+:4]; endfunction function void show_pkt; $display("dst=%h src=%h data=%h crc=%h", pkt1.dst_addr, pkt1.src_addr, pkt1.data, pkt1.crc); endfunction endmodule Two questions about this example: (1) The init function takes a pkt_s structure as an input. When I make the following assignment, one SystemVerilog simulator passes while another reports an error due to the apostrophe in from of the { If I remove the apostrophe, the other SystemVerilog simulator works while the first simulator fails because of the missing apostrophe. init('{4'h9, 4'h6, 32'h1234ABCD, 8'h00}); This may just be an artifact of the simulator versions that I am using but I want to make sure that everyone agrees that this function call SHOULD include the apostrophe (??) (and this will be fixed in upcoming releases). (2) Second question. Look at the following display command. $display("dst=%h src=%h data=%h crc=%h", pkt1.dst_addr, pkt1.src_addr, pkt1.data, pkt1.crc); Is there some way to unpack the struct (almost like aggregate de-assignment) so that the display command could be written something like: $display("dst=%h src=%h data=%h crc=%h", pkt1); and the fields propagate to the separate display formats in the field-order declared within the struct? I don't think there is such a thing, but if there is I would like to hear about it (would be nice!) Regards - Cliff ---------------------------------------------------- Cliff Cummings - Sunburst Design, Inc. 14314 SW Allen Blvd., PMB 501, Beaverton, OR 97005 Phone: 503-641-8446 / FAX: 503-641-8486 cliffc@sunburst-design.com / www.sunburst-design.com Expert Verilog, SystemVerilog, Synthesis and Verification Training
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