VHDL Error (10028): Can't resolve multiple constant drivers for net...

josyb:

What you say makes a great deal of sense. What I am struggling with is the how to structure all the code dealing with assigning values to a signal in a process.

I'm coming from a 'C' background, with all of the associated language. I can see I'm heading in the right direction, but I'm not there yet!

The real problem I'm running into is how to pass information between processes. At the moment the only thing i can see that can perform this are things defined as SIGNAL.

I need to go back and rethink the functionality distribution of the code.

kaz:

Formatting of my code is now been sorted, thanks.

tricky:

I'm not surprised I have lots of problems in my code.

Buffers: I will return to using SIGNALS as opposed to BUFFERS. I used BUFFERS to solve problems, but not in the correct way.

1. button1<=status; duh! obvious!

2. I don't understand the sentence starting "Usually, its better to create...." I get the feeling that it is something fairly fundamental.

waits: OK, so as a rule, try and use sensitivity lists, as opposed to waits. I'm learning that clocking of logic is not a good idea. Infact, it sounds like using any derived clocks is a poor idea.

Part of my code is generating a baud rate, which is a form of a clock. Is there a preferred/recommended way of doing this? I have yet to find examples of a baud rate generators (and how to use them correctly).

There is your problem: I'm not quite sure I understand this. The reason I created the set_button1() procedure was to ensure that there was only line of code that alters the value of button1. But it seems I've not solved the problem. It sounds like the compiler is treating a PROCEDURE or a FUNCTION as a method of inserting code (macro like), as opposed to calling a generic procedure (I think I've just let out my 'C' like thinking here).

This bring me back to a comment I made answering josyb response: how to I pass information/triggers between processes that do not violate SIGNAL rules? Either I've not understood what I've been reading, or I've not read the relevant sections.

thanks for all your responses, please keep them coming!

Robert Hodkinson.