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Altera_Forum
Honored Contributor
16 years agoBeMicro UART Interface no data on RxD
Hi @ all I tried the following vhdl process code in order to receive data from pc com interface: com: process (clk) variable temp : std_logic_vector(47 downto 0) := "0000000000000000000...
Altera_Forum
Honored Contributor
16 years ago --- Quote Start --- I thought The process itself is clk sensitive, every Time The clk Signal changes The Process gets executed. --- Quote End --- It's common misunderstanding in VHDL design. It possibly works in simulation but never in synthesized logic (FPGA hardware). VHDL is a hardware description language, not a procedural programming language that is executed sequentially. Examine existing UART designs. They performing everything in an edge sensitive process block. P.S.: Regarding rxd polarity, I really meant "in addition". Without a reasonable edge sensitive process trigger, it can't work either.