I'm trying to rewrite this code using generate statements (Verilog HDL):
integer j;
always#(posedge cpu_clk) begin
// ACCU_RST
if(RAM[3][7]) begin
RAM[3][7] <= 1'b0;
for(j = 10; j <= 15; j = j + 1)
RAM[j] <= 8'b0;
end
// CPU write
RAM[addr + 0] <= in_valid && cmd && (addr + 0 <= 9 || addr + 0 >= 16) ? data_in[8 * 0 + 7:8 * 0] : RAM[addr + 0];
RAM[addr + 1] <= in_valid && cmd && (addr + 1 <= 9 || addr + 1 >= 16) ? data_in[8 * 1 + 7:8 * 1] : RAM[addr + 1];
RAM[addr + 2] <= in_valid && cmd && (addr + 2 <= 9 || addr + 2 >= 16) ? data_in[8 * 2 + 7:8 * 2] : RAM[addr + 2];
RAM[addr + 3] <= in_valid && cmd && (addr + 3 <= 9 || addr + 3 >= 16) ? data_in[8 * 3 + 7:8 * 3] : RAM[addr + 3];
//CPU read
out_valid <= !cmd && in_valid;
out_data[8 * 0 + 7:8 * 0] <= !cmd && in_valid ? RAM[addr + 0] : out_data[8 * 0 + 7:8 * 0];
out_data[8 * 1 + 7:8 * 1] <= !cmd && in_valid ? RAM[addr + 1] : out_data[8 * 1 + 7:8 * 1];
out_data[8 * 2 + 7:8 * 2] <= !cmd && in_valid ? RAM[addr + 2] : out_data[8 * 2 + 7:8 * 2];
out_data[8 * 3 + 7:8 * 3] <= !cmd && in_valid ? RAM[addr + 3] : out_data[8 * 3 + 7:8 * 3];
end
Yet I recieve the following errors if I try this:
// CPU write
for(i = 0; i <= 3; i = i + 1) begin
if(in_valid && cmd && (addr + i <= 9 || addr + i >= 16))
RAM[addr + i] <= data_in[8 * i + 7:8 * i];
end
//CPU read
out_valid <= !cmd && in_valid;
for(i = 0; i <= 3; i = i + 1) begin
if(in_valid && !cmd)
out_data[8 * i + 7:8 * i] <= RAM[addr + i];
end
ERROR: i is not a constant value.
(error points to data_in[8 * i + 7:8 * i] and out_data[8 * i + 7:8 * i])
Another try, using two always blocks, one for generate, one for ACCU_RST yields multiple drivers for RAM (duh).
Last try:
genvar i;
always#(posedge cpu_clk) begin
if(ACCU_RST) begin
RAM[3][7] <= 1'b0;
for(j = 10; j <= 15; j = j + 1)
RAM[j] <= 8'b0;
end
// CPU write cmd
for(i = 0; i <= 3; i = i + 1) begin :CPU_W
if(in_valid && cmd && (addr + i <= 9 || addr + i >= 16))
RAM[addr + i] <= data_in[8 * i + 7:8 * i];
end
//CPU read cmd
out_valid <= !cmd && in_valid;
for(i = 0; i <= 3; i = i + 1) begin :CPU_R
if(in_valid && !cmd)
out_data[8 * i + 7:8 * i] <= RAM[addr + i];
end
end
That yields:
ERROR: Procedural assignment to a non-register i is not permitted,
left-hand side should be reg/integer/time/genvar
(and points to i = 0 and to i = i + 1).
For this you shouldn't use a generate block. The generate for loop must exist outside of an always block. And a values must only be assigned in one always block to be synthesizable. Take the below example, RAM[2] can be assigned when addr==0 on the third loop (i==2), when addr==1 on the second loop (i==1), and when addr==2 on on the first loop (i==0). Three separate always blocks which is a synthesizable error.
genvar i;
generate
for(i=0; i<4; i++) begin
always #(posedge clk)
if (in_valid && cmd && (addr + i <= 9 || addr + i >= 16))
RAM[addr + i] <= data_in[8*i + 7 : 8*i];
end
endgenerate
Skip the generate and use a standard for loop inside the always block. Use indexed part-select (references here and here):
integer i; // <-- not genvar
always #(posedge cpu_clk) begin
/* ... your other code ... */
// CPU write cmd
for (i = 0; i < 4; i = i + 1) begin :CPU_W
if (in_valid && cmd && (addr + i <= 9 || addr + i >= 16))
RAM[addr + i] <= data_in[ 8*i +: 8];
end
//CPU read cmd
out_valid <= !cmd && in_valid;
for (i = 0; i < 4; i = i + 1) begin :CPU_R
if (in_valid && !cmd)
out_data[ 8*i +: 8] <= RAM[addr + i];
end
end
Related
void blur(int height, int width, RGBTRIPLE image[height][width])
{
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)
{
int red_total = 0;
int blue_total = 0;
int green_total = 0;
int number_counted = 0;
for (int k = -1; k <= 1; k++)
{
for (int l = -1; l <= 1; l++)
{
if (i + k <= height && i + k >= 0 && j + l <= width && j + l >= 0)
{
blue_total += image[i+k][j+l].rgbtBlue;
red_total += image[i+k][j+l].rgbtRed;
green_total += image[i+k][j+l].rgbtGreen;
number_counted ++;
}
}
}
image[i][j].rgbtBlue = blue_total / number_counted;
image[i][j].rgbtRed = red_total / number_counted;
image[i][j].rgbtGreen = green_total / number_counted;
}
}
return;
}
Why is that section && operators?
if (i + k <= height && i + k >= 0 && j + l <= width && j + l >= 0)
I ran it with || operators because my understanding is that under the guise of the problem IF any of those conditions are satisfied there is no block to add. Yet why is it that when I run it under || it returns segmentation fault whereas if I run it with && the problem works out?
Thank you for answering!
All of those conditions have to be true or else the array operations will be invalid.
e.g. if i+k > height then image[i+k] is invalid.
Also I think you have some "off by one problems. image is [height][width] so valid values are [0..height-1] and [0..width-1] so the checks should be more like if (i + k < height && i + k >= 0 && j + l < width && j + l >= 0)
I have a string s containing different types of brackets : () and [] . How can I balance a string of this type with the minimum possible number of reversals ? I can replace any bracket with any other one.
For example : Cost for [)(] is 2, it becomes [()]. Cost for [](( is 1, it becomes []() . [(]) is not balanced.
A more complex example : )[)([)())] can be turned to ([])[(())] in 4 changes, but can also be turned to [()(()())] in 3 steps, which is the least number of modifications to make it balanced.
How can I solve the problem ?
First approach I came with is O(n^3) dynamic programming.
Let match(i, j) be the number of replaces you have to make in order to make s[i] and s[j] as () or []. So match(i, j) can be either 0, 1 or 2.
Consider dp[i][j] = the minimum cost to balance the subsequence from i to j in your brackets array. Now you will define dp[i][i + 1] as:
dp[i][i + 1] = match(i, i + 1)
Now the general rule is that we take the overall minimum between dp[i + 1][j - 1] + match(i, j) and min(dp[i][j], dp[i][p] + dp[p + 1][j]) for any i < p < j. Obviously, the result will be held in dp[1][n]. There is a C++ solution (I'll also upload a python program in about 15 minutes when I'll be done with it - not so strong with python :P).
#include <iostream>
#include <string>
using namespace std;
int dp[100][100];
string s;
int n;
int match(char a, char b) {
if (a == '(' && b == ')') {
return 0;
}
if (a == '[' && b == ']') {
return 0;
}
if ((a == ')' || a == ']') && (b == '(' || b == '[')) {
return 2;
}
return 1;
}
int main() {
cin >> s;
n = s.length();
s = " " + s;
for (int i = 0; i <= n; ++i) {
for (int j = 0; j <= n; ++j) {
dp[i][j] = 0x3f3f3f3f;
}
}
for (int i = 1; i < n; ++i) {
dp[i][i + 1] = match(s[i], s[i + 1]);
}
for (int k = 3; k <= n; k += 2) {
for (int i = 1; i + k <= n; ++i) {
int j = i + k;
dp[i][j] = min(dp[i][j], dp[i + 1][j - 1] + match(s[i], s[j]));
for (int p = i + 1; p <= j; p += 2) {
dp[i][j] = min(dp[i][j], dp[i][p] + dp[p + 1][j]);
}
}
}
cout << dp[1][n] << '\n';
/*for (int i = 1; i <= n; ++i) {
for (int j = 1; j <= n; ++j) {
cout << dp[i][j] << ' ';
}
cout << '\n';
}*/
return 0;
}
Edit:
Here you go Python :)
s = input()
n = len(s)
inf = 0x3f3f3f3f
def match(x, y):
if x == '(' and y == ')':
return 0
if x == '[' and y == ']':
return 0
if (x == ')' or x == ']') and (y == '(' or y == '['):
return 2
return 1
# dp[i][j] = min. cost for balancing a[i], a[i + 1], ..., a[j]
dp = [[inf for j in range(n)] for i in range(n)]
for i in range(n - 1):
dp[i][i + 1] = match(s[i], s[i + 1])
for k in range(3, n, 2):
i = 0
while i + k < n:
j = i + k
dp[i][j] = min(dp[i][j], dp[i + 1][j - 1] + match(s[i], s[j]))
for p in range(i + 1, j, 2):
dp[i][j] = min(dp[i][j], dp[i][p] + dp[p + 1][j])
i += 1
print(dp[0][n - 1])
#for i in range(n):
# for j in range(n):
# print(dp[i][j], end = ' ')
# print()
I'm trying to create 32 color stripes via VGA.
generate
genvar i;
always #(posedge vga_clk) begin
if (x_num == 10'h3FF)
RGB = 16'b00000_000011_00011;
for (i = 1; i < 32; i = i + 1) begin: rgb_gen
40: else if ((i * 20 < x_num) && (x_num < (i + 1) * 20)) begin
RGB = RGB << i;
end
end
end
endgenerate
But there is an error:
Error (10170): Verilog HDL syntax error at top.v(40) near text "else"; expecting "end"
In my mind, result have to be following:
always #(posedge vga_clk) begin
if (x_num == 10'h3FF)
RGB = 16'b00000_000011_00011;
else if ((0 < x_num) && (x_num < 20))
RGB = RGB << 0;
else if ((20 < x_num) && (x_num < 40))
RGB = RGB << 1;
..................
end
What am I doing wrong?
You cannot embed a generate block in the middle of a procedural block of code. I think what you want is
integer i;
always #(posedge vga_clk) begin
RGB = 0;
if (x_num == 10'h3FF)
RGB = 16'b00000_000011_00011;
else
for (i = 1; i < 32; i = i + 1)
if ((i * 20 < x_num) && (x_num < (i + 1) * 20))
RGB = RGB << i;
end
I am trying to create a parametrized circuit for the multiplication stage of a BCD Wallace Tree Multiplier, which I implemented in Orcad. The trouble I'm having is that I need to calculate the bit positions that each two digits that result from BCD multiplication will inhabit.
Here is my code:
module bcd_mult_1_n #(parameter N = 8)
(input [N * 4 - 1:0] num1, num2, output reg [2 * 4 * N * N - 1:0] partProds);
genvar i, j;
generate
for(i = 0; i < N; i = i + 1) begin : dig1
for(j = 0; j < N; j = j + 1) begin : dig2
localparam lsd = posLSD(i, j);
localparam msd = posMSD(i, j);
bcd_mult_1 bcd_mult(num1[i * 4 + 3:i * 4], num2[j * 4 + 3:j * 4],
partProds[msd * 4 + 3:msd * 4], partProds[lsd * 4 + 3: lsd * 4]);
end
end
endgenerate
In the above code, numPrev(i + j) needs to return a value calculated something like this
int numPrev(int x) {
int acc = 0;
for(int i = x; i > 0; i++) acc = acc + 2 * i;
return acc;
}
Thanks to help from #Morgan I have created the following function; the logic is meant to count up and down a sort of triangle of values which rise from 1 to N and back down to 1.
function integer posLSD;
input integer x, y;
integer weight;
integer acc;
integer num;
integer i;
weight = x + y;
acc = 0;
if(weight >= N) num = N - 1;
else num = weight;
for(i = num; i > 0; i = i - 1)
acc = acc + 2 * i;
if(weight >= N) begin
for(i = 2 * N - weight; i <= N; i = i + 1) begin
acc = acc + 2 * i;
end
acc = acc + N - weight + y - 1;
end
else
acc = acc + y;
posLSD = acc;
endfunction
function integer posMSD;
input integer x, y;
integer acc;
integer weight;
acc = posLSD(x, y);
weight = x + y;
if(weight < N) acc = acc + weight + 1;
else acc = acc + 2 * N - weight - 1;
posMSD = acc;
endfunction
How could I achieve this functionality? If needed, I could use SystemVerilog constructs.
When I change to use a function I get the error Packed dimension must specify a range. I think you need to think about your partProds width and connections.
Using a function:
module bcd_mult_1_n #(
parameter N = 8
) (
input [N * 4 - 1:0] num1,
input [N * 4 - 1:0] num2,
output reg [2 * 4 * N * N] partProds
);
integer prev = 1;
genvar i, j;
generate
for(i = 0; i < N; i = i + 1) begin : dig1
for(j = 0; j < N; j = j + 1) begin : dig2
bcd_mult_1
bcd_mult(
num1[i * 4 + 3:i * 4],
num2[j * 4 + 3:j * 4],
partProds[numPrev(i+j) + 2*j + i + 1],
partProds[numPrev(i+j) + j]
);
end
end
endgenerate
function numPrev;
input integer x ;
integer acc;
begin
acc = 0;
for(int ij = x; ij > 0; ij++) begin
acc = acc + 2 * ij;
end
numPrev = acc;
end
endfunction
endmodule
module bcd_mult_1(
input [3:0]a,
input [3:0]b,
input c,
input d
);
endmodule
Example on EDA Playground.
I am trying to transform my C# implementation of Levenstein algorithm into Visual C++ and I am facing this error message
An unhandled exception of type 'System.IndexOutOfRangeException' occurred
The original fully working C# code is
public static int Compute(string s, string t)
{
int n = s.Length;
int m = t.Length;
int[,] d = new int[n + 1, m + 1];
// Step 1
if (n == 0)
{
return m;
}
if (m == 0)
{
return n;
}
// Step 2
for (int i = 0; i <= n; d[i, 0] = i++)
{
}
for (int j = 0; j <= m; d[0, j] = j++)
{
}
// Step 3
for (int i = 1; i <= n; i++)
{
//Step 4
for (int j = 1; j <= m; j++)
{
// Step 5
int cost = (t[j - 1] == s[i - 1]) ? 0 : 1;
// Step 6
d[i, j] = Math.Min(
Math.Min(d[i - 1, j] + 1, d[i, j - 1] + 1),
d[i - 1, j - 1] + cost);
}
}
// Step 7
return d[n, m];
}
Visual C++ code that produces IndexOutOfRangeException is this
int Compute(String^ s, String^ t)
{
int n = s->Length;
int m = t->Length;
array<int,2>^ d = gcnew array<int,2>(n+1 , m+1); //int[,] d = new int[n + 1, m + 1];
// Step 1
if (n == 0)
{
return m;
}
if (m == 0)
{
return n;
}
// Step 2
for (int i = 0; i <= n; d[i, 0] = i++)
{
}
for (int j = 0; j <= m; d[0, j] = j++)
{
}
// Step 3
for (int i = 1; i <= n; i++)
{
//Step 4
for (int j = 1; j <= m; j++)
{
// Step 5
int cost = (t[j - 1] == s[i - 1]) ? 0 : 1;
// Step 6
d[i, j] = Math::Min(
Math::Min(d[i - 1, j] + 1, d[i, j - 1] + 1),
d[i - 1, j - 1] + cost);
}
}
// Step 7
return d[n, m];
}
Is there anything wrong with my array declaration in Visual C++?
This exception occurs because of accessing the index more than its limit.
e.g. limit is n and you are using n+1 th element of an array.
check the value of i and j does it exceeds or and m+1 print the values of i and j so that you can find in which iteration the value exceeds limit.
I soved it , I used vectors instead or array
my 2D array implementation was not corrected , here is the correct implementation in visual C++
int Lev(String^ s, String^ t)
{
int n = s->Length;
int m = t->Length;
vector<vector<int> > d(n+1,vector<int>(m+1));
// Step 1
if (n == 0)
{
return m;
}
if (m == 0)
{
return n;
}
// Step 2
for (int i = 0; i <= n; d[i][0] = i++)
{
}
for (int j = 0; j <= m; d[0][j] = j++)
{
}
// Step 3
for (int i = 1; i <= n; i++)
{
//Step 4
for (int j = 1; j <= m; j++)
{
// Step 5
int cost = (t[j - 1] == s[i - 1]) ? 0 : 1;
// Step 6
d[i][j] = Math::Min(
Math::Min(d[i - 1][j] + 1, d[i][j - 1] + 1),
d[i - 1][j - 1] + cost);
}
}
// Step 7
return d[n][m];
}