Vhdl 次优定时实施警告-F7多路复用器
我试图创建一个I2C总线进行测试,作为我尝试编程DVI Ch7301c的一部分 我正在向它提供测试数据,但是,当我尝试传输数据值hex 77时,它会抛出以下警告:Vhdl 次优定时实施警告-F7多路复用器,vhdl,timing,xilinx,synthesis,spartan,Vhdl,Timing,Xilinx,Synthesis,Spartan,我试图创建一个I2C总线进行测试,作为我尝试编程DVI Ch7301c的一部分 我正在向它提供测试数据,但是,当我尝试传输数据值hex 77时,它会抛出以下警告: Pack:2574 - The F7 multiplexer symbol "I2C_Master/Mmux_bit_cnt[2]_DAT_WR[7]_Mux_45_o_2_f7" and its I1 input driver "I2C_Master/Mmux_bit_cnt[2]_DAT_WR[7]_Mux_45_o_
Pack:2574 - The F7 multiplexer symbol
"I2C_Master/Mmux_bit_cnt[2]_DAT_WR[7]_Mux_45_o_2_f7" and its I1 input driver
"I2C_Master/Mmux_bit_cnt[2]_DAT_WR[7]_Mux_45_o_3" were implemented
suboptimally in the same slice component. The function generator could not be
placed directly driving the F7 multiplexer. The design will exhibit
suboptimal timing.
缩小范围后,它似乎会在case语句中抛出,但只有在发送值hex 77时才会抛出。此外,我可以将值hex 77发送到case语句中的其他位置,而不是直接在when counter SYSCLK_P,--Map输入时钟中
SYSCLK_N=>SYSCLK_N,
--时钟输出端口
SYSCLK=>SYSCLK);
------------------------------------------
---实例化I2C总线驱动程序-------------
I2C_主机:IIC_主机
通用映射(输入时钟=>300000000,--系统时钟
总线(时钟=>300000000/16)
端口映射(时钟=>sysclk,--300 MHz系统时钟(以1/8的速率运行)
重置\u N=>重置\u N,--从dvi初始化器获取重置
ENA=>‘1’,--来自上方的启用信号
ADR=>“1010110”-直接从输入的目标DVI地址
RW=>i2c_-wr,--从初始化器获取R/W
DAT_WR=>i2c_wdata,--从初始化器写入的数据
REG=>i2c_regdata,--目标寄存器
DAT_RD=>打开,--从DVI设备读取的数据(目前处于非活动状态)
忙=>忙,--I2C已完成写入
SCL=>SCL,--直接输出到SCL
SDA=>SDA,--直接输出到SDA
确认错误=>确认错误)--如果从机确认错误,则标记
--------------------------------------------
重置进程:进程(sysclk)
变量计数器:0到4的整数范围;
可变边:布尔--用于检测忙下降沿
开始
如果上升沿(sysclk),则
如果忙='1',则
边:=真--下一个“0”将是边
如果结束;
如果忙='0'且边缘和计数器<3,则
计数器:=计数器+1--增量计数器
边:=假--重置边缘
如果结束;
柜位是
当0=>
i2c_-wr查看一下,您会发现两个F7多路复用器和一个F8多路复用器
FPGA的LUT可以实现每个布尔6输入函数(“F6”)。如果需要7输入函数,则使用两个LUT6和一个F7MUX将此函数映射到CLB
8输入函数需要四个LUT6、两个F7MUX和一个F8MUX
计时比LUT6慢,但比LUT树快
发出警告是为了提醒您描述输入计数较低的功能。如果您更改了代码或某些常量,优化可能再也找不到compact 6输入函数了
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.NUMERIC_STD.ALL;
library UNISIM;
use UNISIM.VComponents.all;
entity I2CBus is
PORT(
SYSCLK_N : IN STD_LOGIC; --system 200MHz differential clock
SYSCLK_P : IN STD_LOGIC;
BTN : IN STD_LOGIC; -- to manually change reset
SCL : INOUT STD_LOGIC; --SCL & SDA lines
SDA : INOUT STD_LOGIC;
SCL_cpy : OUT STD_LOGIC; --SCL & SDA lines
SDA_cpy : OUT STD_LOGIC
);
end I2CBus;
architecture Behavioral of I2CBus is
component IIC_Master is
Generic(input_clock : integer; --system clock
bus_clock : integer);
Port(CLOCK : in STD_LOGIC;
RESET_N : in STD_LOGIC; --Active low
ENA : in STD_LOGIC; --Enable active high
ADR : in STD_LOGIC_VECTOR(6 downto 0); --target address
RW : in STD_LOGIC; --read low, write high
REG : in STD_LOGIC_VECTOR(7 downto 0); --target register
DAT_WR : in STD_LOGIC_VECTOR(7 downto 0); --data to write to slave
DAT_RD : out STD_LOGIC_VECTOR(7 downto 0); --data to read from slave
BUSY : out STD_LOGIC; --high when busy
SCL : inout STD_LOGIC; --serial clock of i2C bus
SDA : inout STD_LOGIC; --serial data on bus
ACK_ERR : buffer STD_LOGIC); --flag if wrong ack from slave
end component;
component DCM
port(
SYSCLK_P : in std_logic; -- Clock in ports 200MHz differential
SYSCLK_N : in std_logic;
-- Clock out ports
SYSCLK : out std_logic --300 MHz clock out
);
end component;
-----Clock signals -------------
signal sysclk : std_logic; --300 mhz system clock
----Internal Signals------------
signal ack_err : std_logic; --error from dvi slave
signal busy : std_logic; --is I2C master busy?
signal slave_dout : std_logic_vector(7 downto 0); --data out from slave
signal reset_n : std_logic; --reset low
signal i2c_wr : STD_LOGIC; --R/W value to send
signal i2c_wdata : STD_LOGIC_VECTOR(7 downto 0); --data to send
signal i2c_regdata : STD_LOGIC_VECTOR(7 downto 0); --target register
begin
--------Instantiate DCM------------------
DCM_Clks : DCM
port map( -- Clock in ports
SYSCLK_P => SYSCLK_P, --Map input clocks directly
SYSCLK_N => SYSCLK_N,
-- Clock out ports
SYSCLK => SYSCLK);
------------------------------------------
---Instantiate I2C Bus Driver-------------
I2C_Master : IIC_Master
Generic map(input_clock => 300000000, --system clock
bus_clock => 300000000 / 16)
Port map(CLOCK => sysclk, --300 MHz system clock (runs at 1/8th that)
RESET_N => RESET_N, --get reset from dvi initialiser
ENA => '1', --enable signal from above
ADR => "1010110", --target DVI address straight from input
RW => i2c_wr, --get R/W from initialiser
DAT_WR => i2c_wdata, --data to write from initialiser
REG => i2c_regdata, -- target register
DAT_RD => open, --data read from DVI device (inactive at present)
BUSY => busy, --I2C finished writing
SCL => SCL, -- output straight to SCL
SDA => SDA, -- output straight to SDA
ACK_ERR => ack_err); --flag if wrong ack from slave
--------------------------------------------
reset_proc : process(sysclk)
variable counter : integer range 0 to 4;
variable edge : boolean; --used to detect busy falling edge
begin
if rising_edge(sysclk) then
if busy = '1' then
edge := true; --next '0' will be an edge
end if;
if busy = '0' and edge and counter < 3 then
counter := counter + 1; --increment counter
edge := false; --reset edge
end if;
case counter is
when 0 =>
i2c_wr <= '0'; --set to write
i2c_regdata <= x"AA"; --send new target register
i2c_wdata <= x"99"; --send new write data
when 1 =>
i2c_regdata <= x"FF";
i2c_wdata <= x"55";
when 2 =>
i2c_regdata <= x"BB";
i2c_wdata <= x"77"; --WARNING occurs here when sending x"77"
when others => null;
end case;
end if;
end process;
reset_n <= not BTN; --reset process;
SDA_cpy <= SDA; --copy SDA & SCL to observable pins
SCL_cpy <= SCL;
end Behavioral;