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Beginner
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can i use quick sorting in HDL(Verilog or VHDL)?

module sort_ex ( clk, rst, out);   parameter SIZE = 10;   input clk, rst; output reg [6:0]out;   reg set_end, loop_check, loop_on1, loop_on2, loop_on3; reg [8:0] arr [SIZE-1:0]; reg [8:0] temp; reg [8:0] pivot; reg [9:0] stack_num;   integer stack [SIZE+2:0]; integer low, high, cnt, first, last, seed, i, loop_temp;     /*initial begin seed = 6; for(i=0; i<SIZE; i=i+1) arr[i] = $random(seed); end */   initial begin arr[0] = 9; arr[1] = 8; arr[2] = 7; arr[3] = 6; arr[4] = 5; arr[5] = 4; arr[6] = 3; arr[7] = 2; arr[8] = 1; arr[9] = 0; end     always @ (posedge clk) begin if(rst) begin stack_num <= 0; set_end <= 0; first <= 0; last <= SIZE-1; stack[stack_num] <= last; stack_num <= stack_num + 1'b1; stack[stack_num] <= first; stack_num <= stack_num + 1'b1; pivot <= 0; cnt <= 0; loop_check <= 1'b0; loop_on1 <= 1'b0; loop_on2 <= 1'b0; loop_on3 <= 1'b0; end else if(!set_end) begin loop_check <= 1'b0; while((loop_check == 0) && (stack_num != 0)) begin stack_num <= stack_num - 1'b1; first <= stack[stack_num]; stack_num <= stack_num - 1'b1; last <= stack[stack_num]; if((last - first + 1) > 1) begin pivot = arr[last]; low <= first - 1; high <= last; //while(low < high) begin for(cnt = 0; cnt < 10; cnt=cnt+1) if(loop_on3 == 0) begin /*while(arr[low+1] < pivot) low = low + 1; low = low + 1;*/   for(low=low; low<last+1; low=low+1) begin if((arr[low+1] >= pivot)&&(loop_on1==0)) begin loop_temp <= low+1; loop_on1 <= 1; end end   low <= loop_temp; loop_on1 <= 1;   /*while(arr[high-1] > pivot) high = high - 1; high = high - 1;*/ for(high=high; high > first-1; high=high-1) begin if((arr[high-1] <= pivot) && (loop_on2 == 0)) begin loop_temp <= high-1; loop_on2 <= 1; end end high <= loop_temp; loop_on2 <= 1; if(low < high) begin temp <= arr[low]; arr[low] <= arr[high]; arr[high] <= temp; end if(low >= high) loop_on3 <= 1; end temp <= arr[low]; arr[low] <= arr[last]; arr[last] <= temp; stack[stack_num] <= last; stack[stack_num+1] <= low + 1; stack[stack_num+2] <= low - 1; stack[stack_num+3] <= first; stack_num <= stack_num + 4; loop_check <= 1; end if(stack_num == 0) set_end <= 1; end end end     endmodule

i want to program quick sorting in Verilog.

this code is compiled in ModelSim, but in quartus, it makes a compilation stuck.

i know Hardware language is different from C/C++...

but i don't know how program quick sorting in Verilog.

i can't find any information in Google..

 

someone helps me how program the sorting module in Verilog.

 

 

 

 

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Employee
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Some of C/C++ coding may not be synthesized correctly even though sometime it can compile successfully. Advice you can copy out what error you had in here or search any solution/hint to that error in quartus help https://www.intel.com/content/www/us/en/programmable/quartushelp/18.0/index.htm#msgs/msgs/wsta_launc...
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Valued Contributor II
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You are writing your verilog code thinking like a sequential C programmer. This code is NOT going to work the way you expect it to:

 

always @ (posedge clk) begin if(rst) begin stack_num <= 0; set_end <= 0; first <= 0; last <= SIZE-1; stack[stack_num] <= last; stack_num <= stack_num + 1'b1; stack[stack_num] <= first; stack_num <= stack_num + 1'b1; pivot <= 0; cnt <= 0; loop_check <= 1'b0; loop_on1 <= 1'b0; loop_on2 <= 1'b0; loop_on3 <= 1'b0; end else

Lines 5 thru 10 in particular are expecting to use the result of a computation in the next line (or so) and that is NOT how the non-blocking '<=' assignment works. It will evaluate the RHS based on current values, then save the result until the trigger event (enclosing posedge CLK with RST set) and then assign the result to the LHS. I can guarantee this is not what you are expecting.

 

You need to go and get a good verilog reference tex.t to understand blocking vs non-blocking assignment, event driven simulation, and the synthesis subset of the verilog language.

 

It should certainly be possible to code a quicksort module in verilog operating on a memory structure, but this is not going to work as written.

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Highlighted
Beginner
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sorry, i show the wrong code.

in my code, every non-blocking '<=' was blocking '='.

i just wrote my code thinking like C.

but if the non-blocking is blocking, i think the code is sequence code. i don't know why didnt operate.

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Valued Contributor II
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Well, even beyond the blocking/non-blocking assignment issue, using constructs like 'for' and 'while' are going to produce non-synthesizable code.

Ok for behavioral simulation, not so much for synthesis.

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