I have Lattice iCE40 HX8K FPGA in 256 BGA package. I want to use one of the available PLL modules to transform external clock frequency of 37MHz to internal clock for use inside of the FPGA of 74MHz.
I used the "Configure PLL Module" in IceCube2 and used the following configuration: - PLL Type section: - GlobalNetworks to be Driven by PLL Output : 1; - Dedicated Clock Pad; - PLL Operation Modes: - No Compensation Mode; - Additional Delay Settings : No; - Frequency: - Input - 37MHz; - Output - 74MHz; - Others - nothing selected;
Then I get the two VHDL files - SO_pll.vhd and SO_pll_inst.vhd. I have file Design.vhd where my code is supposed to go. If I understand correctly Lattice documentation, I need to specify that my Design.vhd (its Entity) is top Level Module, which I did. I need to include SO_pll.vhd in the list of design files in IceCube2, which I did. And last - I need to use the template provided in SO_pll_inst.vhd to instantiate in my main code the PLL by port mapping the PLL signals to signals in my Design.vhd. Here comes the trouble - how to do it?
---Design.vhd---
library IEEE;
use IEEE.std_logic_1164.all;
entity Design is
port(
I_CLK: in std_logic
);
end entity Design;
architecture RTL of Design is
signal S_CLK : std_logic;
signal S_RESET : std_logic;
begin
SO_pll_inst: SO_pll
port map(
REFERENCECLK => I_CLK,
PLLOUTCORE => open,
PLLOUTGLOBAL => S_CLK,
RESET => S_RESET
);
end RTL;
---SO_pll_inst.vhd---Generated by IceCube2
SO_pll_inst: SO_pll
port map(
REFERENCECLK => ,
PLLOUTCORE => ,
PLLOUTGLOBAL => ,
RESET =>
);
---SO_pll.vhd---Generated by IceCube2
library IEEE;
use IEEE.std_logic_1164.all;
entity SO_pll is
port(
REFERENCECLK: in std_logic;
RESET: in std_logic;
PLLOUTCORE: out std_logic;
PLLOUTGLOBAL: out std_logic
);
end entity SO_pll;
architecture BEHAVIOR of SO_pll is
signal openwire : std_logic;
signal openwirebus : std_logic_vector (7 downto 0);
component SB_PLL40_CORE
generic (
--- Feedback
FEEDBACK_PATH : string := "SIMPLE"; -- String (simple, delay,
phase_and_delay, external)
DELAY_ADJUSTMENT_MODE_FEEDBACK : string := "FIXED";
DELAY_ADJUSTMENT_MODE_RELATIVE : string := "FIXED";
SHIFTREG_DIV_MODE : bit_vector(1 downto 0) := "00";
-- 0-->Divide by 4, 1-->Divide by 7, 3 -->Divide by 5
FDA_FEEDBACK : bit_vector(3 downto 0) := "0000";
-- Integer (0-15).
FDA_RELATIVE : bit_vector(3 downto 0) := "0000";
-- Integer (0-15).
PLLOUT_SELECT : string := "GENCLK";
--- Use the spread sheet to populate the values below
DIVF : bit_vector(6 downto 0);
-- Determine a good default value
DIVR : bit_vector(3 downto 0);
-- Determine a good default value
DIVQ : bit_vector(2 downto 0);
-- Determine a good default value
FILTER_RANGE : bit_vector(2 downto 0);
-- Determine a good default value
--- Additional C-Bits
ENABLE_ICEGATE : bit := '0';
--- Test Mode Parameter
TEST_MODE : bit := '0';
EXTERNAL_DIVIDE_FACTOR : integer := 1
-- Not Used by model, Added for PLL config GUI
);
port (
REFERENCECLK : in std_logic; -- Driven by core logic
PLLOUTCORE : out std_logic; -- PLL output to core logic
PLLOUTGLOBAL : out std_logic; -- PLL output to global network
EXTFEEDBACK : in std_logic; -- Driven by core logic
DYNAMICDELAY : in std_logic_vector (7 downto 0); -- Driven by core
logic
LOCK : out std_logic; -- Output of PLL
BYPASS : in std_logic; -- Driven by core logic
RESETB : in std_logic; -- Driven by core logic
LATCHINPUTVALUE : in std_logic; -- iCEGate Signal
-- Test Pins
SDO : out std_logic; -- Output of PLL
SDI : in std_logic; -- Driven by core logic
SCLK : in std_logic -- Driven by core logic
);
end component;
begin
SO_pll_inst: SB_PLL40_CORE
-- Fin=37, Fout=74
generic map(
DIVR => "0000",
DIVF => "0001111",
DIVQ => "011",
FILTER_RANGE => "011",
FEEDBACK_PATH => "SIMPLE",
DELAY_ADJUSTMENT_MODE_FEEDBACK => "FIXED",
FDA_FEEDBACK => "0000",
DELAY_ADJUSTMENT_MODE_RELATIVE => "FIXED",
FDA_RELATIVE => "0000",
SHIFTREG_DIV_MODE => "00",
PLLOUT_SELECT => "GENCLK",
ENABLE_ICEGATE => '0'
)
port map(
REFERENCECLK => REFERENCECLK,
PLLOUTCORE => PLLOUTCORE,
PLLOUTGLOBAL => PLLOUTGLOBAL,
EXTFEEDBACK => openwire,
DYNAMICDELAY => openwirebus,
RESETB => RESET,
BYPASS => '0',
LATCHINPUTVALUE => openwire,
LOCK => open,
SDI => openwire,
SDO => open,
SCLK => openwire
);
end BEHAVIOR;
I just added Design.vhd and SO_pll.vhd to the list of design files. If I run synthesis with Lattice LSE the synthesis is successful, but the placer report says 0/2 PLLs used. If I run Synthesys with Synplify Pro placer report says 1/2 PLLs used,but I really cannot use it since I have not mapped the signals.
When I get the template from SO_pll_inst.vhd and place it inside of the architecture of Design.vhd I get the error message: "ERROR - synthesis: design.vhd(19): so_pll is not declared. VHDL-1241" Well, apparently I am missing something. If it is a template, I would expect just to map my signal and have it running. But no. Either I am doing something wrong, or...I am doing something wrong :) Please help.
