RS232 command interpreter vhdl

Hello Carlhermann,

First of all I want to thank you for your comments and suggestions :o. I was able to solve this issue, part of it was make changes like you suggested before.

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...Additionally you should synchronize the process for concatenating the command to sysclk rather using the outputflag of the UART process for stringent clock synchronous design...

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Also I built a FSM for handling the "commands", the code I sure could be improved a lot in order to be more "compact" or efficient; but at least it is working now.

Here's the code

...
-- Commands FSM
process(sysrst, sysclk, txEnable, rxData)
begin
if sysrst = '0' then
	txEnable	<=	'0';
	txData	<=	(others => '0');
	cmd_ctr	<=	0;
	cmd_state	<=	IDLE;
	commands	<=	(others => '0');
elsif sysclk'event and sysclk = '1' then
case cmd_state is
	when	IDLE	=>	
						txEnable	<=	'0';
						txData	<=	(others	=> '0');
						if rxReady = '1' then
							cmd_state	<=	START_CMD;
						else
							cmd_state	<=	IDLE;
							cmd_rdy	<=	'0';
							cmd_ctr	<=	0;
							commands	<=	(others => '0');
						end if;
	when START_CMD	=>
		case cmd_ctr is
			when 0	=>
						commands	<=	commands(23 downto 0) & rxData;
						cmd_ctr	<=	1;
						cmd_state	<=	START_CMD;
			when 1	=>
						if rxReady = '1' then
							commands	<=	commands(23 downto 0) & rxData;
							cmd_ctr	<=	2;
							cmd_state	<=	START_CMD;
						end if;
			when 2	=>	
						if rxReady = '1' then
							commands	<=	commands(23 downto 0) & rxData;
							cmd_ctr	<=	3;
							cmd_state	<=	START_CMD;
						end if;
			when 3	=>
						if rxReady = '1' then
							commands	<=	commands(23 downto 0) & rxData;
							cmd_ctr	<=	0;
							cmd_state	<=	WHICH_CMD;
						end if;
		end case;															
	when WHICH_CMD	=>
...

Thanks again for your support.

Regards,

Efel