No clock signals found in this design... XST V2P

Jul 27, 2005 1 Replies

I have a top level design with a clock this clock goes into an into a DCM and then into a submodule where the dcm divided clock is monitored with a process statement. and is used with a rising_edge(clk) statement as well



yet ISE (XST) still tells me there is no input clock signal what the heck is going on? do i need to change some synthesis settings? please help



code below:


library ieee; use ieee.std_logic_1164.all; use IEEE.std_logic_unsigned.all; use ieee.numeric_std.all;



-- synthesis translate_off library UNISIM; use UNISIM.VCOMPONENTS.all;



-- synthesis translate_on library XilinxCoreLib;


-- V2P has 198 KB of BRAM



--roughly 50,000 double words



entity system is port ( OPB_Clk : in std_logic; --driven by 100mhz clk



SYS_RESET : in std_logic;



-- all these are big endian A : out std_logic_vector(0 to 31); --A, OE, WE, D are shared flash & sram OE_L : out std_logic; --WE_L : buffer std_logic; WE_L : out std_logic; D : inout std_logic_vector(0 to 31);



SRAM_CS_L : inout std_logic; SRAM_BS_L : out std_logic_vector(0 to 3); -- "bs" signals control "BLE#" and "BHE#"



TRGT_IRQ : in std_logic;



SYS_ACE_CS_N : out std_logic; -- data buffer enable GPIO_CS_N : out std_logic -- data buffer enable



); end system;


architecture structural of system is


component IBUFG port ( O : out std_ulogic; I : in std_ulogic ); end component;



component DCM_INST port ( CLKIN_IN : in std_logic; RST_IN : in std_logic; CLKDV_OUT : out std_logic; CLKIN_IBUFG_OUT : out std_logic; CLK0_OUT : out std_logic; LOCKED_OUT : out std_logic ); end component;



component BUFG port( O : out std_ulogic; I : in std_ulogic ); end component;



-- internal block ram to store read data -- must convert to little endian when plugging in address



component sub_sys is port ( clk : in std_logic; --driven by 100mhz clk A : out std_logic_vector(0 to 31); --A, OE, WE, D are shared flash & sram D : inout std_logic_vector(0 to 31); TRGT_IRQ : in std_logic ); end component;


--------------------------------------------------------------------------------



-- internal signals



-------------------------------------------------------------------------------- signal opb_clk_int : std_logic; signal clk_div_buf : std_logic; signal opb_clk_buf : std_logic; signal dcm_clk0_buf : std_logic; signal locked : std_logic; signal dcm_clk0 : std_logic; signal dcm_clkdv : std_logic;



begin


--------------------------------------------------------------------------------



-- instantiations



--------------------------------------------------------------------------------



sub_system : sub_sys port map ( clk => clk_div_buf, A => A, D => D, TRGT_IRQ => TRGT_IRQ );



buffered_100 : BUFG port map ( I => DCM_CLK0, O => DCM_CLK0_BUF );



buffered_50 : BUFG port map ( I => DCM_CLKDV, O => clk_div_buf --DCM_CLKDV_BUF );



Inst_DCM_INST : DCM_INST port map ( CLKIN_IN => OPB_Clk, RST_IN => SYS_RESET, CLKDV_OUT => DCM_CLKDV, CLKIN_IBUFG_OUT => opb_clk_int, CLK0_OUT => DCM_CLK0, LOCKED_OUT => locked );



SYS_ACE_CS_N


Geoffrey,

What's inside DCM_INST? Could you try connecting a CLK0 output of a DCM (after BUFG) to CLKIN input of a DCM as well?

Vladislav

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required