EE3755 HW 4 Due date : Dec 3 at the class room

We will give the solution.

Problem 1: The following module my_loop is not working.

module my_loop(a,b);

input [15:0] b;

output a;

reg [3:0] a;

reg [3:0] i;

integer s;

initial begin

s = 0;

for(i=0; i<16; i=i+1) s = s + b[i];

a = s;

end

endmodule

//

The above module is not working.

The correct code is:

reg [3:0] a; => reg[4:0] a;

reg [3:0] i; => reg[4:0] i;

a) why the size of “ a “should be more than 4?

b) Why the size of “I ” “should be more than 4?

Problem 2: Draw figure for the module below.

//For those who got 0 deduction at the test, it does not mean your solution is the right one)

// your solution was close one

module adder(sum,a);

input [7:0] a;

output [10:0] sum;

reg [10:0] sum;

integer i;

always @( a ) begin

sum = 0;

for(i=0; i<4; i=i+1) if( i <= a ) sum = sum + i;

end

endmodule

(check your solution with Buildgates synthesizer program)

Problem 3:

a) Write MIPS code for the below c program.

(Test your code with MIPS simulator.)

int print_num(char *c,int n){

int i;

int j;

for(i=0;i <n;++i){

j = c[i] -'a';

if(c[i] != 0) printf("%d\n",j);

}

return 1;

}

b) Write MIPS code for the drive program for the above code…

HINT: for c.

// v =”abcd\0”;

// print_num( v,5);