如何解决 Vivado 中的 "Register/latch pins with no clock driven by root clock pin" 错误?
How to resolve "Register/latch pins with no clock driven by root clock pin" error in Vivado?
作为学习练习,我正在使用 VHDL 在 FPGA 上进行一些 HDMI 实验。在 Vivado (2017.1) 中实现它时,我在时序报告中遇到以下警告:
There are 11 register/latch pins with no clock driven by root clock pin: Hsync_i_reg/Q (HIGH)
我打开了实现的原理图并查找了有问题的引脚。它似乎与其他所有东西都连接到同一个时钟(并且没有在计时报告中标记),所以我对上面的错误指的是什么感到困惑。以下是示意图中的一些截图:
这是违规设计的 VHDL 代码:
library ieee;
use ieee.std_logic_1164.all;
entity ctrl_gen is
generic (
ha: integer := 96; --hpulse
hb: integer := 144; --hpulse+hbp
hc: integer := 784; --hpulse+hbp+hactive
hd: integer := 800; --hpulse+hbp+hactive+hfp
va: integer := 2; --vpulse
vb: integer := 35; --vpulse+vbp
vc: integer := 515; --vpulse+vbp+vactive
vd: integer := 525 --vpulse+vbp+vactive+vfp
);
port (
clk25: in std_logic; --tmds clock (25mhz)
hsync: out std_logic; --horizontal sync
vsync: out std_logic; --vertical sync
hactive: out std_logic; --active portion of hsync
vactive: out std_logic; --active portion of vsync
dena: out std_logic --display enable
);
end entity;
architecture behavioral of ctrl_gen is
signal hsync_i, hactive_i, vactive_i, vsync_i : std_logic;
begin
-- horizontal signals generation
hproc : process (clk25)
variable hcount: integer range 0 to hd := 0;
begin
if rising_edge(clk25) then
hcount := hcount + 1;
if (hcount=ha) then
hsync_i <= '1';
elsif (hcount=hb) then
hactive_i <= '1';
elsif (hcount=hc) then
hactive_i <= '0';
elsif (hcount=hd) then
hsync_i <= '0';
hcount := 0;
end if;
end if;
end process;
-- vertical signals generation
vproc : process (hsync_i)
variable vcount: integer range 0 to vd := 0;
begin
if falling_edge(hsync_i) then
vcount := vcount + 1;
if (vcount=va) then
vsync_i <= '1';
elsif (vcount=vb) then
vactive_i <= '1';
elsif (vcount=vc) then
vactive_i <= '0';
elsif (vcount=vd) then
vsync_i <= '0';
vcount := 0;
end if;
end if;
end process;
dena <= hactive_i and vactive_i;
hsync <= hsync_i;
vactive <= vactive_i;
hactive <= hactive_i;
end behavioral;
经过深思熟虑,我认为警告是在告诉我 Hsync_i_reg/Q 是用于 Vcount 寄存器的时钟,而不是 Hsync_i_reg 本身(如果未连接到根时钟引脚)?
是不是我用的方法不好,不太可能奏效?整体设计不工作,我正在尝试了解是否是这个原因。
谢谢。
我发现了潜在的设计问题。首先是将 variable
用于实际上是时钟信号的对象。其次,您使用生成的信号作为时钟输入。这也不好。
我会将您的代码修改为以下内容(未测试它是否完全符合您之前的代码所做的)
library ieee;
use ieee.std_logic_1164.all;
entity ctrl_gen is
generic (
ha: integer := 96; --hpulse
hb: integer := 144; --hpulse+hbp
hc: integer := 784; --hpulse+hbp+hactive
hd: integer := 800; --hpulse+hbp+hactive+hfp
va: integer := 2; --vpulse
vb: integer := 35; --vpulse+vbp
vc: integer := 515; --vpulse+vbp+vactive
vd: integer := 525 --vpulse+vbp+vactive+vfp
);
port (
clk25: in std_logic; --tmds clock (25mhz)
hsync: out std_logic; --horizontal sync
vsync: out std_logic; --vertical sync
hactive: out std_logic; --active portion of hsync
vactive: out std_logic; --active portion of vsync
dena: out std_logic --display enable
);
end entity;
architecture behavioral of ctrl_gen is
signal hsync_i, hactive_i, vactive_i, vsync_i : std_logic;
signal hcount: integer range 0 to hd-1 := 0;
signal vcount: integer range 0 to vd-1 := 0;
begin
-- horizontal signals generation
hproc : process (clk25)
begin
if rising_edge(clk25) then
if hcount < hd-1 then
hcount <= hcount + 1;
else
hcount <= 0;
end if;
if (hcount=ha-1) then
hsync <= '1';
end if;
if (hcount=hb-1) then
hactive_i <= '1';
end if;
if (hcount=hc-1) then
hactive_i <= '0';
end if;
if (hcount=hd-1) then
hsync <= '0';
end if;
end if;
end process;
-- vertical signals generation
vproc : process (clk25)
begin
if rising_edge(clk25) then
if hcount = hd-1 then -- moment of falling_edge hsync.
if vcount < vd-1 then
vcount <= vcount + 1;
else
vcount <= 0;
end if;
if (vcount=va-1) then
vsync <= '1';
end if;
if (vcount=vb-1) then
vactive_i <= '1';
end if;
if (vcount=vc-1) then
vactive_i <= '0';
end if;
if (vcount=vd-1) then
vsync <= '0';
end if;
end if;
end if;
end process;
dena <= hactive_i and vactive_i;
vactive <= vactive_i;
hactive <= hactive_i;
end behavioral;
我认为:
signal hcount: integer range 0 to hd-1 := 0;
signal vcount: integer range 0 to vd-1 := 0;
不是 hcount
、vcount
的有效合成类型:它应该是 std_logic_vector
作为学习练习,我正在使用 VHDL 在 FPGA 上进行一些 HDMI 实验。在 Vivado (2017.1) 中实现它时,我在时序报告中遇到以下警告:
There are 11 register/latch pins with no clock driven by root clock pin: Hsync_i_reg/Q (HIGH)
我打开了实现的原理图并查找了有问题的引脚。它似乎与其他所有东西都连接到同一个时钟(并且没有在计时报告中标记),所以我对上面的错误指的是什么感到困惑。以下是示意图中的一些截图:
这是违规设计的 VHDL 代码:
library ieee;
use ieee.std_logic_1164.all;
entity ctrl_gen is
generic (
ha: integer := 96; --hpulse
hb: integer := 144; --hpulse+hbp
hc: integer := 784; --hpulse+hbp+hactive
hd: integer := 800; --hpulse+hbp+hactive+hfp
va: integer := 2; --vpulse
vb: integer := 35; --vpulse+vbp
vc: integer := 515; --vpulse+vbp+vactive
vd: integer := 525 --vpulse+vbp+vactive+vfp
);
port (
clk25: in std_logic; --tmds clock (25mhz)
hsync: out std_logic; --horizontal sync
vsync: out std_logic; --vertical sync
hactive: out std_logic; --active portion of hsync
vactive: out std_logic; --active portion of vsync
dena: out std_logic --display enable
);
end entity;
architecture behavioral of ctrl_gen is
signal hsync_i, hactive_i, vactive_i, vsync_i : std_logic;
begin
-- horizontal signals generation
hproc : process (clk25)
variable hcount: integer range 0 to hd := 0;
begin
if rising_edge(clk25) then
hcount := hcount + 1;
if (hcount=ha) then
hsync_i <= '1';
elsif (hcount=hb) then
hactive_i <= '1';
elsif (hcount=hc) then
hactive_i <= '0';
elsif (hcount=hd) then
hsync_i <= '0';
hcount := 0;
end if;
end if;
end process;
-- vertical signals generation
vproc : process (hsync_i)
variable vcount: integer range 0 to vd := 0;
begin
if falling_edge(hsync_i) then
vcount := vcount + 1;
if (vcount=va) then
vsync_i <= '1';
elsif (vcount=vb) then
vactive_i <= '1';
elsif (vcount=vc) then
vactive_i <= '0';
elsif (vcount=vd) then
vsync_i <= '0';
vcount := 0;
end if;
end if;
end process;
dena <= hactive_i and vactive_i;
hsync <= hsync_i;
vactive <= vactive_i;
hactive <= hactive_i;
end behavioral;
经过深思熟虑,我认为警告是在告诉我 Hsync_i_reg/Q 是用于 Vcount 寄存器的时钟,而不是 Hsync_i_reg 本身(如果未连接到根时钟引脚)?
是不是我用的方法不好,不太可能奏效?整体设计不工作,我正在尝试了解是否是这个原因。
谢谢。
我发现了潜在的设计问题。首先是将 variable
用于实际上是时钟信号的对象。其次,您使用生成的信号作为时钟输入。这也不好。
我会将您的代码修改为以下内容(未测试它是否完全符合您之前的代码所做的)
library ieee;
use ieee.std_logic_1164.all;
entity ctrl_gen is
generic (
ha: integer := 96; --hpulse
hb: integer := 144; --hpulse+hbp
hc: integer := 784; --hpulse+hbp+hactive
hd: integer := 800; --hpulse+hbp+hactive+hfp
va: integer := 2; --vpulse
vb: integer := 35; --vpulse+vbp
vc: integer := 515; --vpulse+vbp+vactive
vd: integer := 525 --vpulse+vbp+vactive+vfp
);
port (
clk25: in std_logic; --tmds clock (25mhz)
hsync: out std_logic; --horizontal sync
vsync: out std_logic; --vertical sync
hactive: out std_logic; --active portion of hsync
vactive: out std_logic; --active portion of vsync
dena: out std_logic --display enable
);
end entity;
architecture behavioral of ctrl_gen is
signal hsync_i, hactive_i, vactive_i, vsync_i : std_logic;
signal hcount: integer range 0 to hd-1 := 0;
signal vcount: integer range 0 to vd-1 := 0;
begin
-- horizontal signals generation
hproc : process (clk25)
begin
if rising_edge(clk25) then
if hcount < hd-1 then
hcount <= hcount + 1;
else
hcount <= 0;
end if;
if (hcount=ha-1) then
hsync <= '1';
end if;
if (hcount=hb-1) then
hactive_i <= '1';
end if;
if (hcount=hc-1) then
hactive_i <= '0';
end if;
if (hcount=hd-1) then
hsync <= '0';
end if;
end if;
end process;
-- vertical signals generation
vproc : process (clk25)
begin
if rising_edge(clk25) then
if hcount = hd-1 then -- moment of falling_edge hsync.
if vcount < vd-1 then
vcount <= vcount + 1;
else
vcount <= 0;
end if;
if (vcount=va-1) then
vsync <= '1';
end if;
if (vcount=vb-1) then
vactive_i <= '1';
end if;
if (vcount=vc-1) then
vactive_i <= '0';
end if;
if (vcount=vd-1) then
vsync <= '0';
end if;
end if;
end if;
end process;
dena <= hactive_i and vactive_i;
vactive <= vactive_i;
hactive <= hactive_i;
end behavioral;
我认为:
signal hcount: integer range 0 to hd-1 := 0;
signal vcount: integer range 0 to vd-1 := 0;
不是 hcount
、vcount
的有效合成类型:它应该是 std_logic_vector