Forum Discussion
Altera_Forum
Honored Contributor
Honored ContributorWhen to reset a signal.
In one process I set a command
when X"01" => --continious data read
cont_ram_addr := to_integer(unsigned(addr_bus));
ram_command <= RAM_CONT_WRITE;
when X"02" => --continious data write
cont_ram_addr := to_integer(unsigned(addr_bus));
ram_command <= RAM_CONT_READ;
when X"03" => --read data command
ram_command <= RAM_BYTE_WRITE;
when X"04" => --write data command
ram_command <= RAM_BYTE_READ;
case RamState is
when ST_IDLE =>
if(ram_command > "000") then
case ram_command is
when RAM_CONT_WRITE => RamState <= ST_CONT_WR_RAM;
when RAM_CONT_READ => RamState <= ST_CONT_RD_RAM;
when RAM_BYTE_WRITE => RamState <= ST_WR_RAM;
when RAM_BYTE_READ => RamState <= ST_RD_RAM;
when others => RamState <= ST_IDLE;
end case;
end if;
when ST_WR_RAM => -
--do something
RamState <= ST_IDLE;
when ST_RD_RAM =>
--do something
RamState <= ST_IDLE;
when ST_CONT_WR_RAM =>
-do something
RamState <= ST_IDLE;
when ST_CONT_RD_RAM =>
-- do something
RamState <= ST_IDLE;
5 Replies
Altera_ForumThis is a design choice for the designer. Without knowing the design, it will be impossible to comment.
- Altera_Forum
Looks like you either need to incorporate the command setting logic into the command executing state machine, or at least you need the state machine to be able to communicate with the command setting logic (to reset the command or whatever you need to make the design work). As Tricky said, very hard to give advice from such little information.
- Altera_Forum--- Quote Start --- Looks like you either need to incorporate the command setting logic into the command executing state machine, or at least you need the state machine to be able to communicate with the command setting logic (to reset the command or whatever you need to make the design work). As Tricky said, very hard to give advice from such little information. --- Quote End --- That's the problem. I'd gladly reset ram_command in the second process. But I get Error (10028): Can't resolve multiple constant drivers for net. So I dont know when I'm good to reset the signal.
- Altera_Forum--- Quote Start --- That's the problem. I'd gladly reset ram_command in the second process. But I get Error (10028): Can't resolve multiple constant drivers for net. So I dont know when I'm good to reset the signal. --- Quote End --- Like I said in your other post, you need to communicate between processes with signals. Create a signal for the sole purpose to send a message between the processes that can reset you ram_command signal.
- Altera_Forum--- Quote Start --- Like I said in your other post, you need to communicate between processes with signals. Create a signal for the sole purpose to send a message between the processes that can reset you ram_command signal. --- Quote End --- But who reset the other signal - the one that reset ram_command? And when? Thanks guys. Stupid question. I figured it out.
