Timeline for Identifier not declared in generic map, vhdl
Current License: CC BY-SA 3.0
10 events
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| Nov 3, 2015 at 15:39 | comment | added | andrsmllr | Be aware that you are using VHDL-1993. Some things which don't work with VHDL-1993 may very well be improved in VHDL-2002 or VHDL-2008. Sadly enough, VHDL-2008 is not supported very well by most vendors (Xilinx, Altera, ..). I'm not sure however, if this problem persists in VHDL-200X. At least with Xilinx ISE/Vivado I think the way you assign the port is demoted to a warning. | |
| Nov 3, 2015 at 15:13 | comment | added | user8469759 | Yeah i'm freaking out for god sake, it's terrible to debug the vhdl code. So was at least my explanation correct? | |
| Nov 3, 2015 at 15:09 | comment | added | andrsmllr |
Also you answered your question yourself: — The name is an indexed name whose prefix is a locally static name, and every expression that appears as part of the name is a locally static expression. Since m is not locally static the whole expression e.g. x(m - 2 downto 0) is not a locally static expression, thus the error. Another work around that should fix this is to declare a constant which is assigned the generic m. This constant can then be used in a locally static expression.
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| Nov 3, 2015 at 14:57 | comment | added | andrsmllr | Great! Requiring work arounds like this is why VHDL is said to be verbose ;-) | |
| Nov 3, 2015 at 14:33 | comment | added | user8469759 | Since the problem arises with the port map, i solved by declaring a signal x_loc, with the desired mapping, and then port the x in componentEntity into x_loc, so i avoided the problem. I was hoping in something shorter... but it's fine. | |
| Nov 3, 2015 at 14:32 | comment | added | user8469759 | Your last statement doesn't work too (because the expression isn't a locally static name). Locally static name means that the name is a simple name, indexed name or selected name that does involves a static evaluation, locally means that the evaluation depends from the current entity. I had two problem in my code, the first was the wrong use of the generic, which wasn't visible as you pointed out, the second is the the parameter m depends from the top entity, so the expression is globally static instead of local. | |
| Nov 3, 2015 at 13:25 | comment | added | user8469759 | But what's the problem in the updated version? | |
| Nov 3, 2015 at 13:21 | comment | added | andrsmllr |
Oh ok. You could change the port assignment to port map( x => "0" & x(m-2 downto 0) );.
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| Nov 3, 2015 at 13:08 | comment | added | user8469759 | I did as you told me, a new error just came out, see the update. | |
| Nov 3, 2015 at 13:04 | history | answered | andrsmllr | CC BY-SA 3.0 |