所以我试图在 Vivado 中为 ZYBO FPGA 板设计一个“自动售货机”时序电路。然而，每次我试图通过实施阶段时，我都会遇到一堆错误，主要是
[Place 30-58] IO placement is infeasible. Number of unplaced terminals (1) is greater than
number of available sites (0).
The following Groups of I/O terminals have not sufficient capacity:
IO Group: 0 with : SioStd: LVCMOS18 VCCO = 1.8 Termination: 0 TermDir: In RangeId: 1
has only 0 sites available on device, but needs 1 sites.
Term: clk
我确实尝试了 Auto I/O 规划，但最终所做的只是移除了引脚约束。那时它通过了实现，但当然无法生成比特流，因为没有一个端口被映射到引脚。
这是我的 VHDL 设计
LIBRARY ieee;
USE ieee.std_logic_1164.ALL;
ENTITY des_src IS
PORT (
reset : IN std_logic;
clk : IN std_logic;
QDN : IN std_logic_vector(2 DOWNTO 0);
PC : OUT std_logic_vector(1 DOWNTO 0)
);
END des_src;
ARCHITECTURE behavioral OF des_src IS
TYPE statetype IS (Start, Five, Ten, Fifteen, Twenty, Twentyfive, Thirty, Thirtyfive, Fourty, Fourtyfive);
SIGNAL currentstate, nextstate : statetype;
BEGIN
fsm1: PROCESS (QDN, currentstate)
BEGIN
CASE currentstate IS
WHEN Start =>
PC <= "00";
CASE QDN IS
WHEN "000" =>
nextstate <= Start;
WHEN "001" =>
nextstate <= Five;
WHEN "010" =>
nextstate <= Ten;
WHEN "100" =>
nextstate <= Twentyfive;
WHEN OTHERS =>
nextstate <= Start;
END CASE;
WHEN Five =>
PC <= "00";
CASE QDN IS
WHEN "000" =>
nextstate <= Five;
WHEN "001" =>
nextstate <= Ten;
WHEN "010" =>
nextstate <= Fifteen;
WHEN "100" =>
nextstate <= Thirty;
WHEN OTHERS =>
nextstate <= Start;
END CASE;
WHEN Ten =>
PC <= "00";
CASE QDN IS
WHEN "000" =>
nextstate <= Ten;
WHEN "001" =>
nextstate <= Fifteen;
WHEN "010" =>
nextstate <= Twenty;
WHEN "100" =>
nextstate <= Thirtyfive;
WHEN OTHERS =>
nextstate <= Start;
END CASE;
WHEN Fifteen =>
PC <= "00";
CASE QDN IS
WHEN "000" =>
nextstate <=Fifteen;
WHEN "001" =>
nextstate <= Twenty;
WHEN "010" =>
nextstate <= Twentyfive;
WHEN "100" =>
nextstate <= Fourty;
WHEN OTHERS =>
nextstate <= Start;
END CASE;
WHEN Twenty =>
PC <= "00";
CASE QDN IS
WHEN "000" =>
nextstate <= Twenty;
WHEN "001" =>
nextstate <= Twentyfive;
WHEN "010" =>
nextstate <= Thirty;
WHEN "100" =>
nextstate <= Fourtyfive;
WHEN OTHERS =>
nextstate <= Start;
END CASE;
WHEN Twentyfive =>
PC <= "10";
nextstate <= Start;
WHEN Thirty =>
PC <= "01";
nextstate <= Twentyfive;
WHEN Thirtyfive =>
PC <= "01";
nextstate <= Thirty;
WHEN Fourty =>
PC <= "01";
nextstate <= Thirtyfive;
WHEN Fourtyfive =>
PC <= "01";
nextstate <= Fourty;
END CASE;
END PROCESS;
fsm2: PROCESS (reset, clk)
BEGIN
IF (reset = '0') THEN
currentstate <= Start;
ELSIF (clk'EVENT) AND (clk = '1') THEN
currentstate <= nextstate;
END IF;
END PROCESS;
END behavioral;
这是我的限制
##Buttons
##IO_L20N_T3_34
set_property IOSTANDARD LVCMOS33 [get_ports {QDN[0]}]
set_property PACKAGE_PIN R18 [get_ports {QDN[0]}]
##IO_L24N_T3_34
set_property IOSTANDARD LVCMOS33 [get_ports {QDN[1]}]
set_property PACKAGE_PIN P16 [get_ports {QDN[1]}]
##IO_L18P_T2_34
set_property IOSTANDARD LVCMOS33 [get_ports {QDN[2]}]
set_property PACKAGE_PIN V16 [get_ports {QDN[2]}]
##IO_L7P_T1_34
set_property IOSTANDARD LVCMOS33 [get_ports reset]
set_property PACKAGE_PIN Y16 [get_ports reset]
##LEDs
##IO_L23P_T3_35
set_property IOSTANDARD LVCMOS33 [get_ports {PC[0]}]
set_property PACKAGE_PIN M14 [get_ports {PC[0]}]
##IO_L23N_T3_35
set_property IOSTANDARD LVCMOS33 [get_ports {PC[1]}]
set_property PACKAGE_PIN M15 [get_ports {PC[1]}]
create_clock -period 10.000 -name clk -waveform {0.000 5.000} [get_ports clk]
set_input_delay -clock [get_clocks clk] -min -add_delay 0.000 [get_ports {QDN[*]}]
set_input_delay -clock [get_clocks clk] -max -add_delay 0.000 [get_ports {QDN[*]}]
set_input_delay -clock [get_clocks clk] -min -add_delay 0.000 [get_ports reset]
set_input_delay -clock [get_clocks clk] -max -add_delay 0.000 [get_ports reset]
set_output_delay -clock [get_clocks clk] -min -add_delay 0.000 [get_ports {PC[*]}]
set_output_delay -clock [get_clocks clk] -max -add_delay 0.000 [get_ports {PC[*]}]
我正在使用 Vivado 2015.2 并为 ZYBO 开发板进行设计。
任何和所有的帮助表示赞赏。
2015 年 8 月 26 日编辑
好吧，我的代码大部分都在工作。我能够使用
set_property PACKAGE_PIN L16 [get_ports clk]
set_property IOSTANDARD LVCMOS33 [get_ports clk]
create_clock -period 10.000 -name clk -waveform {0.000 5.000} [get_ports clk]
为我的时钟。但是，这个时钟比我想要的（125MHz）快得多，所以我知道我必须使用时钟分频并在约束文件中生成一个时钟，但是我需要将生成的时钟分配给一个引脚吗？是否有人对如何在我当前的 vhdl 代码中包含时钟分频器有任何提示？我只是让它成为另一个进程，并添加另一个端口，还是比这更复杂？