transfer data from process1 to process2

[EDA_hg81]

I have two processes running under the same clock domain.

Process1  ( refclk ) 
	begin
           if (rising_edge(refclk)) then
          end if;   
end process;

process2 ( refclk ) 
	begin
           if  (falling_edge(refclk)) then
         end if;   
end process;

I want to transfer data from process1 to process2.

How I can make sure data can be transferred reliably?

Thanks

 

[mawais]

Hi!
You can use signals to carry data from one process to other. This is the simplest solution i guess.
entity
architecture
signal a: std_logic;
begin
process(clk)
begin
if(clk' event and clk='1') then
a<=x;
end if;
end process;

process(clk)
begin
if(clk' event and clk='0') then
y<=a;
end if;
end process;
end architecture;
And in order to varify that the data has been properly transfered you should write a test bench.
And remember generally the value of a signal is updated after the complete execution of process.
I hope this will work
regrards.
Awais

 

[EDA_hg81]

What I want to do is when process1 is done; the data is transferred to process2.

What are the possible reasons the data is lost?

Thanks.

 

[tspen]

There is a way to complete it .You can use handshake.

 

[mawais]

HI!
There seems no reason of data loss. Well if you can put a pieace of code that can help to understand the problem.
One more thing try taking data on the next rising edge of the clock in process2, i mean instead of initiating process2 on falling edge make it a rising edge as well. then check the results.
Other wise put your code here so that we can discuss.

 

[xtcx]

See,I am not so sure about using falling edge to read the data in process2 ....As it's not a good thing to use both rising and falling edge of the same clk. Instead,use one clk delay and read the data...You won't miss any.....