map error about input signals of state machine that will be trimmed

[Steven Kauffmann]

Hello all,

The following process causes the error about the trimmed signals.

process(output_port_component)
begin
ready <= not(ready);
end process;

The process has to invert the ready signal when the data on the output
port of the component changes. I use this ready signal in a state
machine. In this state machine I check if this ready signal is
changed. During the mapping of this VHDL code I get the error that
some input signals of this state machine will be trimmed. If I put in
comment the process above and also the check on the ready signal in
the state machine than I get no errors.

I can solve the errors by editing the map properties and unset the
option "trim unconnected signals". But than my design is not working
like I would expect. I connected the ready signal to a led available
on the board but this led is not changing. I also connect it to a
scope to see if it was not changing to frequent but that is also not
the case. I'm for 100% sure that the output port of the component is
changing but why not the ready signal?

Thanks in advance

Steven

 

[JK]

The process has to invert the ready signal when the data on the output
port of the component changes. I use this ready signal in a state
machine. In this state machine I check if this ready signal is
changed.

process(state_machine_clock)
begin
if rising_edge(state_machine_clock) then
if (output_port_component'event) then
ready <= (not ready);
end if;
end if;
end process;

Regards,
JK

 

[Steven Kauffmann]

process(state_machine_clock)
begin
if rising_edge(state_machine_clock) then
if (output_port_component'event) then
ready <= (not ready);
end if;
end if;
end process;

The output_port_component is a std_logic_vector and not a std_logic
signal so the event is not usable or am I wrong? When using an event
you also have to specify the level of the signal eg.
(output_port_component'event and output_port_component = '1') the
event alone is not a correct syntax according to the XST synthesizer.

If I use this code
process(state_machine_clock)
begin
if rising_edge(state_machine_clock) then
if (output_port_component(0)'event and output_port_component(0) =
'1') then
ready <= (not ready);
end if;
end if;
end process;

But this gives the following error:
Sequential logic for node <ready> appears to be controlled by multiple
clocks.

And this error is because I use 2 events in 1 process I think.

Regards
Steven