Programming NIOSII interfaced with custom component, using Avalon MM Interface

Your c code looks correct. I think there should be some problem in your custom component register interface logic.

Would you provide that logic?

Or You can verify using NIOS II Modelsim.You can also use signal tap and check whether data is written into your custom component register or not.

Hi, the code look like:

always @(posedge csi_clk or posedge rsi_reset_n) begin // To read

if (rsi_reset_n) begin

end else if (avs_s0_read) begin

avs_s0_readdata = START;

end else begin

avs_s0_readdata = 0;

end

end

always @(posedge csi_clk or posedge rsi_reset_n) begin // To write

if (rsi_reset_n) begin

START <= 0;

DATA <= 0;

end else if (avs_s0_write) begin

case (avs_s0_address)

2'b00 : begin//

START <= avs_s0_writedata;

end

2'b01 : begin

DATA <= avs_s0_writedata;

end

default : begin

DATA <= 0;

end

endcase

end

end

In my C ode, i am trying to write START register (as posted previously) and read back START register.

Please suggest. I need to come out of this issue soon

--- Quote Start ---

Hi, the code look like:

always @(posedge csi_clk or posedge rsi_reset_n) begin // To read

if (rsi_reset_n) begin

end else if (avs_s0_read) begin

avs_s0_readdata = START;

end else begin

avs_s0_readdata = 0;

end

end

--- Quote End ---

Its look like your code is correct. Still you can replace above code with this one

always @(posedge csi_clk or posedge rsi_reset_n)

begin // To read

if (rsi_reset_n)

begin

avs_s0_readdata <= 0;

end

else

begin

case(avs_s0_address)

2'b00 : avs_s0_readdata <= START;

default : avs_s0_readdata <= 0;

endcase

end

end

Apart from this what is the read and write latency of your Avalon interface.You can find it in your .tcl file.If write latency is zero then your write logic is correct and if your read latency is 1 then your read logic is correct.

I have one doubt regarding reset.Is it active high or low? From the name of reset it looks like it is active low and you have used it as a active high. You can also find this from your .tcl file.

Also make practice to use non blocking statement for sequential logic.

Regards,

Krupesh

Hi,

I am able to communicate with the custom component successfully.

Now my final task is to calculate the no of clock cycles consumed by the custom component during the execution.

I also included Signal Tap II in my design. But i don't know how to use that to calculate no of clock cycles.

Please help.

You can use performance counter or interval timer provided by the Altera or

You can implement one counter inside your custom component and add one register to read its value.

I used performance counter, but not able to see anything on the console. Not even the stuff which I was getting before adding the performance counter.

I followed the steps below:

1. Added Performance counter in Qsys Design.

2. Added Timer.

3. Used:

PERF_RESET();

PERF_START_MEASURING();

PERF_BEGIN();

// Here is the code block to be tested.

// I want to know the cycles consumed during this block.

PERF_END();

PERF_STOP_MEASURING();

perf_print_formatted_report();

Please help if i am missing anything in the process.

I have used performance counter long time ago.Its look like that you are doing the same thing. Here is my code

PERF_RESET(PERFORMANCE_COUNTER_0_BASE);

PERF_START_MEASURING(PERFORMANCE_COUNTER_0_BASE);

PERF_BEGIN(PERFORMANCE_COUNTER_0_BASE,1);

// Here is the code block to be tested.

// I want to know the cycles consumed during this block.

PERF_END(PERFORMANCE_COUNTER_0_BASE,1);

int cycles = IORD(PERFORMANCE_COUNTER_0_BASE,4); //Read the value of counter.Note that offset is set to 4.

If it is not working then your should design counter in your custom component and read it using avalon interface for the quick solution.

Thanks a lot zoomkrupesh, cronus10.

With all your help and guidance, I successfully implemented and tested my project.

Regards,

Anuj Agrawal

Hi Anuj,

Would you please share how did you find the solution? So that it will be helpful to other users as well.

Thanks,

Krupesh

For performance evaluation, I used the below template:

PERF_RESET(PERFORMANCE_COUNTER_0_BASE);

PERF_START_MEASURING(PERFORMANCE_COUNTER_0_BASE);

PERF_BEGIN(PERFORMANCE_COUNTER_0_BASE,1);

// Here is the code block to be tested.

// I wanted to know the cycles consumed during this block.

PERF_END(PERFORMANCE_COUNTER_0_BASE,1);

PERF_STOP_MEASURING(PERFORMANCE_COUNTER_0_BASE);

long time;

time = perf_get_section_time(PERFORMANCE_COUNTER_0_BASE, 1);

printf("\n\nTotal cycles consumed in FIR calculation = %ld cycles\n", time);

This returns the no of clock cycles consumed. And by knowing the oscillator frequency, we can calcuate the total time consumed in the block.

Thanks,

Anuj