Got a quick newbee question. I'm using some source files from the VHDL cookbook which describe a simple CPU. Many of the files use null waveform elements:
architecture behaviour of buffer_32 is begin b_driver: process (en, a) begin if en = '1' then b
Hi, you are trying to synthesize a model that is only useful (and meaningful) for simulation.
For a deeper explanation of assigning the null-statement to a signal you better ask the guys at comp.lang.vhdl.
The synthesis tools ignore the after Statements, but can't ignore a missing assignment to signal b, so you get an error.
What value should be assigned to b when en ='0' ? "null" is nothing physical, it can either be '0','1' or 'Z'. So my best guess is :
architecture behaviour of buffer_32 is begin b_driver: process (en, a) begin if en = '1' then b Got a quick newbee question. I'm using some source files from the VHDL
I've never seen "null" assigned before. If you want to assign a value to "b" but you don't care what the value is, then use "X", as in:
if en = '1' then b
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