在将fifo代码实例化到我的顶层模块时,我遇到了另一个难题.我想从我的串行端口(接收子系统)存储一些数据,说欢迎来到FPGA的世界",然后我想取回它,例如当按下fpga板上的按钮或FIFO已满时.我写了我的fifo代码和串行通信代码.想法是从键盘发送的数据->接收子系统-> FIFO->传输子系统->超级终端.我目前使用的是8位宽度的fifo,说28位深度只是为了存储一些小数据.在这方面请帮我如何实现它.我有来自接收器的字节保存在register_save中. fifo代码
I come across one more difficulty while instantiate the fifo code to my top module. I want to store some set of data say "WELCOME TO THE WORLD OF FPGA" from my serial port ( receiving subsystem) then i want to retrieve it back say when button on fpga board is pressed or FIFO is full. I have my fifo code and serial communication code written. Idea is data sent from keyboard ->receiving subsystem -> FIFO -> transmitting subsystem -> hyperterminal. I am at present using fifo of 8 bit wide and say 28 deep just to store some small data. Please help me in this regard how can I implement it.I have byte coming from receiver saved in register_save. fifo code
inst_bit8_recieve_unit : entity work.byte_recieve_8N1 port map ( ck => ck, reset => reset, new_byte_in_buffer => new_byte_in_buffer, byte_read_from_buffer => byte_read_from_buffer, recieve_buffer => register_save, JA_2 => JA(2)); ---------------------FIFO instantiate------------------------------- inst_of_fifo_Recieve_unit : entity work.fifo generic map (B => data_bits, W => fifo_width) port map ( ck => ck, reset => reset, rd => rd_rx, wr => wr_rx, write_data => num_recieved, read_data => num_recieved_fifo, empty => empty_rx, full => full_rx ); inst_bit8_transmit_unit : entity work.byte_transmit_8N1 port map ( ck => ck, reset => reset, send_byte_ready => send_byte_ready, send_byte_done => send_byte_done , send_buffer => num_send, JAOUT_0 => JAOUT ); proc_send5byte: process(ck, reset, state_byte5, send_byte_done, num_send, state_button_0, num_recieved_fifo, rd_rx) begin if reset = '1' THEN state_byte5 <= idle; send_byte_ready <='0'; num_send <= "00000000" ; else if rising_edge(ck) then case state_byte5 is when idle => ---- in this, if btn(0) is high i.e pressed then only state_byte5 will go to next state if state_button_0 = transit_pressed then state_byte5 <= byte; end if; -----=============================================================== when byte => if (not empty_rx = '1') then if send_byte_ready ='0' and send_byte_done = '0' then ----here if condition is satified the send_byte_ready will be set send_byte_ready <='1'; --------- shows next byte is ready num_send <= num_recieved_fifo; rd_rx <='1'; end if; end if; if send_byte_ready = '1' and send_byte_done = '1' then --- during load state send_byte will be resets send_byte_ready <='0'; rd_rx <= '0'; state_byte5 <= idle; ----------- go back to idle end if; --end if; ---=============================================================== when others => state_byte5 <= idle; ------------- for other cases state state _byte5 will be in idle send_byte_ready <= '0'; rd_rx <= '0'; end case; end if; end if; end process; proc_recieving_byte : process (ck, reset, register_save, new_byte_in_buffer, full_rx, num_recieved, wr_rx) begin if reset = '1' then byte_read_from_buffer <= '0'; else if rising_edge(ck) then if full_rx = '0' then if new_byte_in_buffer = '1' and byte_read_from_buffer = '0' then byte_read_from_buffer <= '1'; wr_rx <= '1'; num_recieved(7 downto 0 ) <= register_save( 7 downto 0); end if; end if; if new_byte_in_buffer = '0' then byte_read_from_buffer <= '0'; wr_rx <= '0'; end if; --end if; end if; end if; end process;现在只需添加更正后的代码就可以了.当增加fifo的深度时,会出现问题.当depth> 2时,每三个字节就会丢失. 请帮忙,为什么我会丢失数据.
Just added the corrected code now which seems to be working. Problem araises when increase the depth of fifo. When depth>2 then every third byte is missing. Please help, why I am loosing data.
推荐答案fifo的原理是先进先出.您不必管理它.
The principe of a fifo is First In First Out. You have not to manage it.
然后存储数据,您再次执行此操作以存储另一个值.
then the data is store, you do it again to store another value.
当您要读取所有数据时(Fifo已满/任何情况)
When you want to read all data (Fifo full / any case you want)
将读取使能"位设置为"1",每个时钟周期,您都会收到一个数据.
You set Read enable bit to '1' and every clock cycle, you will receive a data.
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