Hi, I'm encountering the following "Warning: Found pins functioning as undefined clocks and/or memory enables". I've gone into the "Classic Timing Analysis Settings", set an individual clock and applied it to the correct node but it doesn't have an effect on the error. Does anyone have any ideas on how to fix the warning? Any help would be greatly appreciated. Thanks, Jesse

Have you some code you can post? Difficult to analyse without that...

Without seeing your code or .qar archive, this one sounds like you are using a signal IO pin as a clock input. The FPGA clock pins give you low skew and latency and should be preferred. You can use signal pins that connect to register or memory clock pins but the latency (delay from pin to clock pin inside chip) is much higher and sometimes timing wont work.

--- Quote Start --- llandis Re: Found pins functioning as undefined clock Without seeing your code or .qar archive, this one sounds like you are using a signal IO pin as a clock input. The FPGA clock pins give you low skew and latency and should be preferred. You can use signal pins that connect to register or memory clock pins but the latency (delay from pin to clock pin inside chip) is much higher and sometimes timing wont work. --- Quote End --- You we're right llandis; I checked the pins again and I am using a dedicated input pin and not an actual clock pin, but even changing the pin to one of the dedicated clock pins I still get the error. I've attached my code below. I'm still yet to refine the timing, I want to get the code correct before playing around with that. LIBRARY ieee; USE ieee.std_logic_1164.ALL; ENTITY ClkTest IS PORT ( clk : IN STD_LOGIC; -- system clock lcd_enable : IN STD_LOGIC; -- latches data into lcd controller lcd_bus : IN STD_LOGIC_VECTOR( 9 DOWNTO 0 ); -- data and control signals busy : OUT STD_LOGIC := '1'; -- lcd controller busy / idle feedback rs, rw : OUT STD_LOGIC; -- setup/data, and read/write e1, e2 : OUT STD_LOGIC; -- enable for the lcd lcd_data : OUT STD_LOGIC_VECTOR( 7 DOWNTO 0 )); -- data signals for the lcd END ClkTest; ARCHITECTURE behav OF ClkTest IS TYPE CONTROL IS( power_up, initialize, ready, send ); SIGNAL state : CONTROL; CONSTANT freq : INTEGER := 20; -- system clock frequency in MHz BEGIN PROCESS( clk ) VARIABLE clk_count : INTEGER := 0; -- event counter for timing BEGIN IF RISING_EDGE( clk ) THEN CASE state IS -- wait 20 ms to ensure Vcc has risen and required LCD wait is met WHEN power_up => busy <= '1'; IF( clk_count < ( 20000 * freq )) THEN -- wait 20 ms clk_count := clk_count + 1; state <= power_up; ELSE -- power-up complete clk_count := 0; rs <= '0'; rw <= '0'; lcd_data <= "00110000"; -- function set command (1) state <= initialize; END IF; -- cycle through initialize sequence WHEN initialize => busy <= '1'; clk_count := clk_count + 1; IF( clk_count < ( 5000 * freq )) THEN -- wait 5 ms state <= initialize; ELSIF( clk_count < ( 5010 * freq )) THEN -- function set command (2) lcd_data <= "00110000"; e1 <= '1'; e2 <= '1'; state <= initialize; ELSIF( clk_count < ( 6000 * freq )) THEN -- wait 1 ms state <= initialize; e1 <= '0'; e2 <= '0'; ELSIF( clk_count < ( 6010 * freq )) THEN -- function set command (3) lcd_data <= "00110000"; e1 <= '1'; e2 <= '1'; state <= initialize; ELSIF( clk_count < ( 7000 * freq )) THEN -- wait 1 ms state <= initialize; e1 <= '0'; e2 <= '0'; ELSIF( clk_count < ( 7010 * freq )) THEN -- function set (8-bits, 1 line, 5x7 font) lcd_data <= "00110000"; e1 <= '1'; e2 <= '1'; state <= initialize; ELSIF( clk_count < ( 8000 * freq )) THEN -- wait 1 ms state <= initialize; e1 <= '0'; e2 <= '0'; ELSIF( clk_count < ( 8010 * freq )) THEN -- display off lcd_data <= "00001000"; e1 <= '1'; e2 <= '1'; state <= initialize; ELSIF( clk_count < ( 9000 * freq )) THEN -- wait 1 ms state <= initialize; e1 <= '0'; e2 <= '0'; ELSIF( clk_count < ( 9010 * freq )) THEN -- clear display lcd_data <= "00000001"; e1 <= '1'; e2 <= '1'; state <= initialize; ELSIF( clk_count < ( 29000 * freq )) THEN -- wait 20 ms state <= initialize; e1 <= '0'; e2 <= '0'; ELSIF( clk_count < ( 29010 * freq )) THEN -- entry mode set (increment mode, entire shift off) lcd_data <= "00000110"; e1 <= '1'; e2 <= '1'; state <= initialize; ELSIF( clk_count < ( 30000 * freq )) THEN -- wait 1 ms state <= initialize; e1 <= '0'; e2 <= '0'; ELSIF( clk_count < ( 30010 * freq )) THEN -- display on (cursor on, blink off) lcd_data <= "00001110"; e1 <= '1'; e2 <= '1'; state <= initialize; ELSIF( clk_count < ( 31000 * freq )) THEN lcd_data <= "00000000"; e1 <= '0'; e2 <= '0'; state <= initialize; ELSE clk_count := 0; busy <= '0'; state <= ready; END IF; -- check for busy flag and then latch in the instruction WHEN ready => IF( lcd_enable = '1' ) THEN busy <= '1'; rs <= lcd_bus(9); rw <= lcd_bus(8); lcd_data <= lcd_bus( 7 DOWNTO 0 ); clk_count := 0; state <= send; ELSE busy <= '0'; rs <= '0'; rw <= '0'; lcd_data <= "00000000"; clk_count := 0; state <= ready; END IF; -- send instructions to the lcd WHEN send => busy <= '1'; IF( clk_count < ( 50 * freq )) THEN busy <= '1'; IF( clk_count < freq ) THEN e1 <= '0'; e2 <= '0'; ELSIF( clk_count < ( 14 * freq )) THEN e1 <= '1'; e2 <= '1'; ELSIF( clk_count < ( 27 * freq )) THEN e1 <= '0'; e2 <= '0'; END IF; clk_count := clk_count + 1; state <= send; ELSE clk_count := 0; state <= ready; END IF; END CASE; END IF; END PROCESS; END ARCHITECTURE behav;

--- Quote Start --- llandis Re: Found pins functioning as undefined clock Without seeing your code or .qar archive, this one sounds like you are using a signal IO pin as a clock input. The FPGA clock pins give you low skew and latency and should be preferred. You can use signal pins that connect to register or memory clock pins but the latency (delay from pin to clock pin inside chip) is much higher and sometimes timing wont work. --- Quote End --- You were correct llandis; I was using a dedicated input pin as a clock input, but even changing to a dedicated clock pin the error is still there. I've attached the code below. I'm still yet to refine the timing, I want to get the code compiled without errors and get the test bench working first. LIBRARY ieee; USE ieee.std_logic_1164.ALL; ENTITY ClkTest IS PORT ( clk : IN STD_LOGIC; -- system clock lcd_enable : IN STD_LOGIC; -- latches data into lcd controller lcd_bus : IN STD_LOGIC_VECTOR( 9 DOWNTO 0 ); -- data and control signals busy : OUT STD_LOGIC := '1'; -- lcd controller busy / idle feedback rs, rw : OUT STD_LOGIC; -- setup/data, and read/write e1, e2 : OUT STD_LOGIC; -- enable for the lcd lcd_data : OUT STD_LOGIC_VECTOR( 7 DOWNTO 0 )); -- data signals for the lcd END ClkTest; ARCHITECTURE behav OF ClkTest IS TYPE CONTROL IS( power_up, initialize, ready, send ); SIGNAL state : CONTROL; CONSTANT freq : INTEGER := 20; -- system clock frequency in MHz BEGIN PROCESS( clk ) VARIABLE clk_count : INTEGER := 0; -- event counter for timing BEGIN IF RISING_EDGE( clk ) THEN CASE state IS -- wait 20 ms to ensure Vcc has risen and required LCD wait is met WHEN power_up => busy <= '1'; IF( clk_count < ( 20000 * freq )) THEN -- wait 20 ms clk_count := clk_count + 1; state <= power_up; ELSE -- power-up complete clk_count := 0; rs <= '0'; rw <= '0'; lcd_data <= "00110000"; -- function set command (1) state <= initialize; END IF; -- cycle through initialize sequence WHEN initialize => busy <= '1'; clk_count := clk_count + 1; IF( clk_count < ( 5000 * freq )) THEN -- wait 5 ms state <= initialize; ELSIF( clk_count < ( 5010 * freq )) THEN -- function set command (2) lcd_data <= "00110000"; e1 <= '1'; e2 <= '1'; state <= initialize; ELSIF( clk_count < ( 6000 * freq )) THEN -- wait 1 ms state <= initialize; e1 <= '0'; e2 <= '0'; ELSIF( clk_count < ( 6010 * freq )) THEN -- function set command (3) lcd_data <= "00110000"; e1 <= '1'; e2 <= '1'; state <= initialize; ELSIF( clk_count < ( 7000 * freq )) THEN -- wait 1 ms state <= initialize; e1 <= '0'; e2 <= '0'; ELSIF( clk_count < ( 7010 * freq )) THEN -- function set (8-bits, 1 line, 5x7 font) lcd_data <= "00110000"; e1 <= '1'; e2 <= '1'; state <= initialize; ELSIF( clk_count < ( 8000 * freq )) THEN -- wait 1 ms state <= initialize; e1 <= '0'; e2 <= '0'; ELSIF( clk_count < ( 8010 * freq )) THEN -- display off lcd_data <= "00001000"; e1 <= '1'; e2 <= '1'; state <= initialize; ELSIF( clk_count < ( 9000 * freq )) THEN -- wait 1 ms state <= initialize; e1 <= '0'; e2 <= '0'; ELSIF( clk_count < ( 9010 * freq )) THEN -- clear display lcd_data <= "00000001"; e1 <= '1'; e2 <= '1'; state <= initialize; ELSIF( clk_count < ( 29000 * freq )) THEN -- wait 20 ms state <= initialize; e1 <= '0'; e2 <= '0'; ELSIF( clk_count < ( 29010 * freq )) THEN -- entry mode set (increment mode, entire shift off) lcd_data <= "00000110"; e1 <= '1'; e2 <= '1'; state <= initialize; ELSIF( clk_count < ( 30000 * freq )) THEN -- wait 1 ms state <= initialize; e1 <= '0'; e2 <= '0'; ELSIF( clk_count < ( 30010 * freq )) THEN -- display on (cursor on, blink off) lcd_data <= "00001110"; e1 <= '1'; e2 <= '1'; state <= initialize; ELSIF( clk_count < ( 31000 * freq )) THEN lcd_data <= "00000000"; e1 <= '0'; e2 <= '0'; state <= initialize; ELSE clk_count := 0; busy <= '0'; state <= ready; END IF; -- check for busy flag and then latch in the instruction WHEN ready => IF( lcd_enable = '1' ) THEN busy <= '1'; rs <= lcd_bus(9); rw <= lcd_bus(8); lcd_data <= lcd_bus( 7 DOWNTO 0 ); clk_count := 0; state <= send; ELSE busy <= '0'; rs <= '0'; rw <= '0'; lcd_data <= "00000000"; clk_count := 0; state <= ready; END IF; -- send instructions to the lcd WHEN send => busy <= '1'; IF( clk_count < ( 50 * freq )) THEN busy <= '1'; IF( clk_count < freq ) THEN e1 <= '0'; e2 <= '0'; ELSIF( clk_count < ( 14 * freq )) THEN e1 <= '1'; e2 <= '1'; ELSIF( clk_count < ( 27 * freq )) THEN e1 <= '0'; e2 <= '0'; END IF; clk_count := clk_count + 1; state <= send; ELSE clk_count := 0; state <= ready; END IF; END CASE; END IF; END PROCESS; END ARCHITECTURE behav;

Is this all of the code? can you post the .qar file?

Found pins functioning as undefined clock | Altera Community

13 Replies

Altera_Forum
Honored Contributor
10 years ago
Hmmm, a bit of an old device eh....

I don't have Quartus 9.0 installed on my machine any more - is that surprising?! However, opening and compiling your project in Quartus 14.1, having changed the device family to something newer, does not produce the warning you mention.

So, it could be a bug in Quartus 9.0sp2, although they usually iron out bugs by service pack 2. Can I recommend that you update your environment and use a modern device? Do you have to use ACEX1K?

Cheers,
Alex
Altera_Forum
Honored Contributor
10 years ago
--- Quote Start ---
Tricky
Re: Found pins functioning as undefined clock
What version of quartus are you using? you would be far better off using Timequest with SDC constraints

--- Quote End ---

I'm using Quartus 9.0sp2, unfortunately I need to use ACEX1K and this version of quartus is the last one that has compatibility with the ACEX devices.

I worked out what was causing the warning. One of the default settings for the Classic Timing Analyzer is to ignore all user-defined clocks. Once I turned that off the warning went away.
Altera_Forum
Honored Contributor
10 years ago
Glad you got this working!

Forum Discussion

Found pins functioning as undefined clock

13 Replies

Recent Discussions

Quartus 20.1std compilation fails for Quartus map - Device 10AS057K2F40I1SG

Is Quartus Prime Pro 22.4 Compatible with Stratix 10 NX Series Device?

Timing analysis - long combinational path

QuartusPro 25.3 Crashed after using the Signal Tap Logic Analyzer

Duplicate_hierarchy_depth / duplicate_register