Can't resolve multiple constant drivers

[EDA_hg81]

cant resolve multiple constant drivers for net

I have a top module which keeps receiving the data from another module (spi_decoder).

This top module is going to transfer the received data( inside datain_reg) to outside.

u1: spi_decoder
port map
	(
	refclk          => refclk,
	dintrig         => dintrig,
	douttrigack  => douttrigack,
	command    => datain_reg,
	
	douttrig      => douttrig,
	dintrigack   => dintrigack,
	fbackdata   => dataout_reg
	);

The code to transfer the data content of dataout_reg is the follow:

if ( spiclkr       = '1'and spiclk = '1' ) then
       dataout           <= dataout_reg(15); 
       dataout_reg    <= dataout_reg(14 downto 0) & '1';
end if;

I got the following error:

Error (10028): Can't resolve multiple constant drivers for net "dataout_reg[15]" at spi_top.vhd.....

What is the reason?

 

[FvM]

You are apparently using dataout_reg as assignment target in different processes or different locations in concurrent code. This would be the case, e.g. if spi_decoder.fbackdata is an output or inout port.

 

[EDA_hg81]

Yes. you are right.


The spi_decoder is going to output the data which going be sent by the following code to MCU :

if ( spiclkr       = '1'and spiclk = '1' ) then 
       dataout           <= dataout_reg(15); 
       dataout_reg    <= dataout_reg(14 downto 0) & '1'; 
end if;

I have tried to recaptured the output data from spi_decoder but didn’t work.

What I should do?