Search Engine


Add Question

161 Threads found on Negedge
Hi, Normally, you wouldn't add so much of logic to the reset condition in RTL and you wouldn't use the sequential clocking block always @ (posedge or negedge) for signals other than clocks and resets. If you want to sample the address pins , assign the incoming address to a register on the rising edge of clock and then in an always_comb block yo
I have no lint errors but few lint warnings in my design example :- assign enable=clk & b; always @(negedge clk) begin . . . . . end But the lint throws a warning that the clk is used for different purposes. so can I avoid this warning ? if no,what are the consequences that have to be faced in real time circuit?
if a clock is only posedge, why would the sdf capture it's negedge behavior?
As a concept, it is odd to intentionally create an async reset that is actually a sync reset. The Verilog always construct describes an asynchronous reset. You might say that it's odd in some way that an asynchronous input is described by a negedge event. The synthesis template for a edge triggered register with asynchronous
For example, it can not be used for Key press rise/fall edge detect, but why it can be used for clock or reset? Thank you!
What I want to do is to detect the raise of signal1 then at the fall of signal2 I want to do some logic but it must be in this order, something like this. always@(posedge signal1) begin @(negedge signal2) begin \\ do some logic end end how to synthesize this with Verilog? Thanks in advance. [url=obrazki.elek
My Comments: 1. Why have you used the negedge of the clock? it is more usual to use the posedge. It would mean this block would not be usuable by the majority of designs. 2. I would rather the addr_out is registered. This means other users dont need to worry about the combinatorial path delay in to their logic. 3. Have you tried synthesising this
Hi, Please let me know , what will be the optimized verilog code of below:- reg control_pin_ton_delay_cntr; always @ (posedge clk_i or negedge nrst_i) begin if (!nrst_i) control_pin_ton_delay_cntr <= 33'd0; else if (enable_i) begin if (control_on_i) control_pin_ton_delay_c
Hi All, How to stitch a couple of negedge flops in the design where most of the flops are posedge? How to balance chains where only few flops are negedge but most flops are posedge? Is it possible to combine posedge and negedge flops in the same chain? Thank you!
If ur clock is 10 ns and if the launch is at 0ns then the capture will be at 10 ns. If you are seeing capture at 5 ns, then it must be capturing data on the negedge of clock. Otherwise you must have constrained it accordingly. Go back to the RTL and check this particular timing path.
You didn't follow the Verilog template for synthesizable sequential code always @ (posedge clk or negedge rst) begin if(!rst) begin clk_out <= 1'bz; count <= 8'b0;; end else begin count <= count + 1; // all additional clock edge sensitive actions must go here[
Hi , the below code uses dff for mod3 counter design . rst generated (using expression1) does not work,where as rst generated (using expression 2) works . what is the reason ? module dff(output reg q,output qn,input d,clk,reset); always @(posedge clk or negedge reset) begin if(!reset) q<=1'b0; else q<=d; end assign qn=~
Hi all, Is there is any upper limit in the sensitivity list for a combinatorial always block..? For eg : If the combinatorial always block code is like : always @ (posedge a or posedge b or negedge c...) begin end My question is : Is there like only 2 elements must be present inside the always block or can we write more..? Than
Is it OK to use both positive and negative edge flip flops on the same clock in the same design from perspective of place & route tools? Is it going to make timing analysis impossible? Note that it won't have combinational logic depending on the outputs of both a posedge and a negedge sensitive flop at the same time.[/QUO
None of the three complies to the templates for synthesizable Verilog (e.g. IEEE Std 1364.1) - the event list of an always block modelling edge sensitive logic must contain only posedge and negedge events - an event can't act on both edges
initial begin // has race condition. reset = 1’b0; #20 reset = 1’b1; #40 reset = 1’b0; end reset = 1’b0 will cause race condition only in case the design is modeled to use asynchronous active low reset as follows. always @ (posedge clk or negedge reset) if (!reset) q <= 1'b0; else q <= d; Because the tool does not guara
HI. I'm using like following that dcm dcm_inst ( .CLKIN_IN ( fclk), .USER_RST_IN( 1'b0 ), .CLKFX_OUT( ), .CLKIN_IBUFG_OUT(clk_out_0 ), .LOCKED_OUT( lock ) ); ... assign reset_n = lock; ... always @(posedge clk_out_0, negedge reset_n) be
Dear all, I've been working with Modelsim SE6.6 for years and all my simulation designs work fine. But today when I immigrate to Modelsim SE 10.1c, they don't. For example, a process like this: always @(posedge clk or negedge reset_n) if(!reset_n) message_type = 0; else if(cnt_reg == Packet_length) message_type = `head;
well you have wrote 5 dividers by 2, so first flop divide by 2 second flop divide by 4 third flop divide by 8 fourth flop divide by 16 fifth flop divide by 32 If you want to divide by 10, it is more easy to made a counter on clock, at reset start to 0, and when it reachs 9, set back to 0... always(posedge clk, negedge nreset) if
Hi all, How we can use the parameter as bit width in verilog for a CONSTANT value representation. For example : parameter VAL = 11; always @ ( posedge CLK or negedge RESETn ) begin if ( !RESETn ) begin count <= {VAL{1'b0}}; end else begin if ( count == 11'h5FF[/C