Search the Community

Hello I decide to assemble papilio one myself, is it possible to replace it's original spi flash with AT45DB161D-SU or AT45DB321D-SU? Thanks.

Hello I have a Problem i have a DAC that is controlled by the Papilio one 250k. I have a 512 byte array with a sine wave stored in it and I read the array to a IO port. Now the problem: It works most of the time if I programm it only to the FPGA. By working I mean that i can see a beautiful sine wave at the oszi. If I programm it several times it works not always, but the programming of the FPGA is so quick I can try until it works. If it doesn't work the wave form is periodic, not a sine tough. But this tells me that the read of the array works but not the write. If I programm the SPI flash it doesn't work and I get a wave form but it isn't a sine at all. I initalize the array a such: type memory_t is array(0 to 511) of std_logic_vector(7 downto 0);-- Declare the RAMsignal ram_bank : memory_t;and i access it as so: -------------------------------------------------------------------------- write Portprocess(clk_200)begin if(falling_edge(clk_200)) then if(w_en = '1') then ram_bank(to_integer(unsigned(add_w))) <= ram_in; end if; end if;end process; -------------------------------------------------------------------------- read Portprocess(clk_200)begin if(rising_edge(clk_200)) then if(r_en = '1') then ram_out <= ram_bank(to_integer(unsigned(add_r))); end if; end if;end process;I tried to run both processes at the rising edge but this doesn't work at all. The read and write is controlled by a FSM, there is never a read and write at the same time. As you can see I use the ram at 200MHz, is this to fast? I use a microblaze MCS to controll the hole thing, so the MCS has the array static in it and writes it to the dac controller fsm, it stores it in the array and after that it is read periodical. If anyone has a clue. Ohm dac_man.vhd