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i_read_en <='1'; i_data <= mem(to_integer(r_reg)); wait for 6000 ns; These are not concurrently running statements they are sequential (a program) so it executes i_data <= mem(to_integer(r_reg)); once then sits there at the wait for 6000 ns; statement for 6000 ns of time before executing the next (...)
@(posedge ticker) is not synthesizable, it's only used in simulation testbenches as an event control to wait until the rising edge of a signal. For edge triggered logic that is synthesizable you have to use always @ (posedge ticker) if you want to synthesize the module. This is a bad design as ticker is used as a clock when
If you want to have delay in vhdl without "wait" statement, see this post. Another way to implement wait statement for is, by implementing a RAM based shift register. The length of RAM should be equal to (REQUIRED DELAY / CLOCK PERIOD).
"wait" statement cannot be synthesis ... Yes it can, but its not the recommended style. The following will synthesise to a register: process begin wait until rising_edge(clk) q <= d; end process;
VHDL for loops are unrolled, they are not software for loops. You should be using a counter and a while loop until the count reaches terminal count. Not exactly sure how the for loop would deal with the wait for 10 ns; statement, I suspect it's ignored, but would have to actually try a test case to be sure. Act
with flip-flops and the the clock used to drive the signals shown? i.e. wait (delay) isn't synthesizable. Based on your question I think you are attempting to write software (the wrong way) instead of hardware (the right way).
Do you hear at all? Timing statements, e.g. wait with timeout are not synthesizeable. Please review post #17.
That is testbench code, and the error indicates you are trying to synthesise it (which you cant) or there is no wait statement in the process. I cant see all the code - is there a wait statement?
@(posedge a) is just a timing statement. Ie. wait until the next rising edge of a. always @(posedge a) means the code here will be executed for every rising edge of a. Hence why you cannot put an always in a task, as a task is meant to be called externally, not have code looping forever.
I assume you know this code is not synthesisable as a single wait statement is no use for synthesis, it is for simulation only. So is the real type. This code looks far to much like software code, and hence will never work. I suggest finding a good text book on digital logic design. Working through the exercises and starting your code again. Befor
A terminating wait statement should stop further process schedule.
Yes, a netlist is just a list of nodes and what is connected to each of them. It is only a connection list, it holds no representation of the schematic or logic diagram layout. Back annotation is the process of automatically going through a netlist and updating it when a change has been made to the schematic. For example, if you renumbered gates/c
c) and d) are both guaranteed to pass because each event executes in a separate active queue. a) and b) are both race conditions because all three events are generated in the same active queue. There's no guaranteed ordering how those events will show up in the separate thread containing wait_order statement. However, I'm guessing most imple
for the solution of this u can use goto statement and let the arduino wait for command check this out i have rewritten the code with ur requirement void int() { val=digitalRead(pinB); // read data one: if(pinB == HIGH) { Serial.println("PINA ON"); //write serially goto two;} else {goto one; two: if(pinB == LOW) {
Hi, I saw your replies in the forum and felt encouraged to post this question. Thanks for providing your expertise. I have a VHDL test bench that is associated with both implementation and simulation (as I would like to run P&R simulation). I just want to define my clock with a certain time period. Say clock = '1', wait for 2.5ns.....clock
#20 means "wait 20 time units before proceeding to execute the immediately following statement". #20; means "wait 20 time units before proceeding to execute the immediately following statement, and oh BTW the immediately following statement is the empty statement". "Empty (...)
wait statement is not possible in synthesizable RTL/
Have you considered using wait statement instead of the assignment delay? wait (expression) statement
Hi All, I am just stumbled with one of the process that i need to execute for my current assignment? I tried above method what is mentioned in question but didn't worked out. Can anyone provide me an easiest way out for following function: I have to write testcases in verilog for my VHDL based DUT.. This testcases should generate rand
hi I wrote a program counter on that counter program is running in between i have to stop by pressing a switch for this i wrote this code void main() { // for(p0=0x00;p0<=0xf0;p0++) { wait(500); if(c1=0) //<---------------c=0 is a an assignment statement break; } } Here c1 act as
Hi, as far as I know a sensitivity list is like a wait at the end of a process so Code1 is similar to process begin --- wait on a,b; end process; This is a little bit different to 2 because after start the process is executed once regards
I am trying to design a tic tac toe game for a project. I need to detect the players first move and then wait 2 seconds before the machine makes a move. I wanted to make the move by the machine in the same "process statement" after the player makes his move but I can't add in a delay inside the process. Should I use a counter and enable this
Can I use a variable instead of time in wait statement. Instead of wait for 10 ns; can it be wait for t_period ns; where t_period is defined as a constant?
You can add a while(IR) While(1) { If(IR==1) { count++; servonewposition(); delay(1000); servooldposition(); while(IR); // the above code will be executed once and the execution will wait here until IR becomes 0 } } Alex
the wait statement is only appropriate for simulation. Otherwise stick the data into a memory and use a counter to wait for 100ms. 100ms is a very long time to wait, you may need a BIG buffer to cope with all the backed up data.
Try adding a "wait;" line just before the "End process" statement.
the key point is you have used the wait statement inside a procedure. This is valid VHDL, but only for simulation. It is not allowable for synthesis (as the error has said). Also, wait until t_clk2 = '1' is not synthesisable. you need: wait until t_clk2'event and t_clk2 = '1'; or wait until (...)
I haven't coded in ASM on PIC's before, but the general procedure is: 1. Set up A/D Converter control bits (ADCON0, per the tutorials you provided) 2. Set up clocking ratio for correct settling time 3. Initiate ADC sample 4. wait for sample to become available 5. Read value from register 6. Make if statement to compare ADC value to the value
Yes, the logical OR operator is the || and not the ^ what you have used, mohideen. @miskol It is unfortunate the while loop here (it may be unnecessary to wait will be), the original "multiple if" structure doesn't wait And an ELSE statement is also possible later ...
I think there was some mistakes in ur program.Use 0b instead of "0xb" to represent binary. I presume smoke sensor was connected to the AN0/RA0 of the ADC.U need to configure the ADC first.PORTA=0xb00000000 is a wrong statmnt.Ur pgm required to wait for the input ie,sensor==1.
In VHDL whether wait statement is synthesizable or not... if it is partially synthesizable in which kind of statement it is synthesisable
The wait statement is used to wait in a particular loop but it is not synthesized as in real time in hardware there in no wait state. Use a counter equal to the time you want the wait statement to execute. Keep on incrementing the counter and write a if loop or a condition that unless your (...)
Hi, Can I use wait statement in procedure in VHDL. Regards Added after 16 minutes: HI Myself got the answer. Synchronous logic could be implemented in procedure using if statement not wait statement. For example.. procedure load_rc is begin start_count <= '1'; -- (...)
hi to every one here in the below mentioned code i am getting error on wait sout, sout is my memory , how to use the meory in wait statement in verilog, i am not getting any error in vhdl.tell me the solution soon. reg sout ; always begin wait sout for (y=1;y<=nby2by3;y=y+1) temp =so
Hi all, I've trying to simulate a simple state machine with VHDL code below: library ieee; use ieee.std_logic_1164.all; entity p82 is port(a, c, clk, rst: in std_logic; x: out std_logic); end p82; architecture behavior of p82 is type state is (stateA, stateB); signal pr_state, nx_state: state; begin -----Lowe
This is a typical counter which counts until 31 with every clock coming in but im havin this error Error (10398): VHDL Process statement error at count31.vhd(27): Process statement must contain only one wait statement why can't i have more than more than 1 wait statement in the process, (...)
Hi, You can use the after or wait statement. Exemples: wait for 10 ns; s<='1'; or s<='1' after 10 ns;
Heloo dear, I want to make cumulative histogram in VHDL. I am using for loop with wait ststement. It runs for ever. I need to run this for loop only once and then stop. Can any one tell me how it is possible. Thanks
Hi please post good veriog questions here .That can helpful to everyone to update our knowledge dailybasis. Here i am posting some questions today. 1. What is the use of "wait" statement in verilog.Where we can use this statement in verilog program. 2. What is the difference between "wait " and (...)
I try to write the finite state verilog program that need to wait sometime in current state before go to next state. I used example : repeat (10) @(posedge clk); But error appear like this: ERROR:Xst:850 - a.v line 32: Unsupported Event Control statement. Is there any other method to do.
hi there are 3 ways 1. a wait statement at the end or the beginning of the process eg. wait on a if 'a' changes then the process with re-evaluate 2. a sensitivity list in the process eg. process (sensitivity list) --process (a) 3. and if statement with an event good luck
I would like to set a default value for a signal or a port in VHDL. For signal I've seen a post speaking about some solutions: 1) process without activity list and a wait; (wait without until) but Quartus wan't a until after the wait statement. 2) if (now < 1ps). Does it works in hardware or only in simulation? I (...)
Dear all, What's the major difference between "after" and "wait for"?
Tell me if I'm wrong, isn't wait statement not synthesisble? Probably I have use VHDL for a couple of months and the synthesis tools may have changed. Read again original question - it has nothing about synthesisable requirements. Just behaviour. BTW, "wait" statement is synthesisable - of course, not the form (...)
wform <= '0'; wait for 8 ns ; wform <= '1'; wait for 13 ns ; wform <= '0'; wait for 50 ns ; wform <= '1'; ... for a testbench... not for synthesis purpose !