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Need some more information about Trimmed index [CDFG-420]

Last post Fri, Mar 30 2007 10:53 AM by archive. 2 replies.
 Started by archive 30 Mar 2007 10:53 AM. Topic has 2 replies and 1190 views
• Fri, Mar 30 2007 10:53 AM

• archive
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Need some more information about Trimmed index [CDFG-420]
 While using RTL compiler I get the following warning message. [CDFG-420] Trimmed index 'portIn' of signal 'startT0' from 2 bits to 1 bits in file The code for above is : parameter PORTS = 4; input wire [1:0]    portIn; input wire [3:0]    cntIn; reg [PORTS -1:0]        pauseDa; case (cntIn)             0: pauseDa[portIn] <=  x; I noticed that in other instances, when I used an integer instead of a binary number, it gave the same warning. As soon as I converted 0 to 1'b0 and 1 to 1'b1, this warning was not issued any more. In the above case, whenever, a bus was used as the index, it issues the above warning.  From the code above, we know pauseDa can have 4 values and portIn can address 4 locations.  But the warning says trimming index to 1 bit. There was no such problem when integers were used for indexing.  (in a for loop).  So, I modified the code as follows, int portIn_int;                                                                                             assign portIn_int = portIn;         case (cntIn)             0: pauseDa[portIn_int] <= x; But I continue to get the same warning.  Trimmed index 'portIn_int' of signal 'pauseDa' from 32 bits to 2 bits The problem is even though the RTL and netlist can be verified each time using verplex, I have to still go through the logs to make sure that all these warnings are ok. Alternatively, I could set: set_attr hdl_trim_target_index false but it mentions that the design is not optimized.  I did verify, that there is a slight increase in area with the above setting to false.  Default is true.  Any suggestions or similar experiances are appreciated. Thanks, Amar.   Originally posted in cdnusers.org by adudyala
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• Fri, Mar 30 2007 10:56 AM

• archive
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RE: Need some more information about Trimmed index [CDFG-420]
 Sorry, I put the wrong Warning number. The correct one is : [CDFG2G-617]Thanks,AmarOriginally posted in cdnusers.org by adudyala
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• Fri, Mar 30 2007 4:36 PM

• archive
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RE: Need some more information about Trimmed index [CDFG-420]
 Hi Amar, just tried the following code: module debug ( input wire [1:0] portIn, input wire [3:0] cntIn, in1, output wire [3:0] out1 ); parameter PORTS = 4; reg [PORTS -1:0] pauseDa; // wire integer portIn_int; // assign portIn_int = portIn; always @(cntIn or portIn or in1) begin case (cntIn) 0: pauseDa[portIn] <= in1; endcase // case(cntIn) end // always @ (cntIn) assign out1 = pauseDa; endmodule // debug and I can see the CDFG2G-617 when I do the mod you did. In that case, it makes sense to me since integers are 32 bits and pauseDa is 2 hence the tool has to trim or else you could give up some optimizations. I noticed that your thread talks about another signal for which you do not show the code > Trimmed index 'portIn' of signal 'startT0' from 2 bits to 1 bits in file It probably is a similar issue. If you can share the code with startT0 I can probably help you out. I am using 6.2-s010, what version are you using ? take care, gh-Originally posted in cdnusers.org by grasshopper
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 Started by archive at 30 Mar 2007 10:53 AM. Topic has 2 replies.
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