Update pixel.cpp

pixel.cpp

-#include <stdio.h>
-#include <hls_stream.h>
-#include <ap_axi_sdata.h>
-#include<math.h>
-#include <string.h>
-
-using namespace std;
-typedef ap_int<32> apint;
-typedef ap_axis<32,0,0,0> pkt_t;
-typedef hls::stream< pkt_t > stream;
-
-//Initializations
-static int count_streams = 0;    //counter of data input streams
-static long long charIn=0;       // to store binary values for each charachter decimal val
-static long long final_char=0;   // binary value of decoded data
-int addNum=0;                    // holds lsb of CharIn
-static int decNum = 0;           //holds the decimal value for all characters
-static int decimalCounter = 0;   //used to shift to other charachter decimal value
-static int decimalOut = 0;       // holds the decimal value of the characters (decoding)
-int lastDecimalVal;              //holds decimal value of one character
-
-long long convert(int n);
-int convertBinInt(long long n);
-void decrypt(int data);
-void toAscii(char *c);
-int getDecimal(int n);
-pkt_t tmpA;
+#include "pixel.hpp"
 
 void pixel(apint &in_decimal,
-        apint selector,
-		apint stream_count,
-		stream &din,
-		stream &dout
+           apint selector,
+		   apint stream_count,
+		   stream &din,
+		   stream &dout
 ) {
 	#pragma HLS INTERFACE ap_ctrl_none port=return
-    #pragma HLS INTERFACE s_axilite port=in_decimal
-    #pragma HLS INTERFACE s_axilite port=selector
-	#pragma HLS INTERFACE s_axilite port=stream_count
+    #pragma HLS INTERFACE s_axilite port=in_decimal     // ascii values for the characters(word)
+    #pragma HLS INTERFACE s_axilite port=selector       // to select the mode (encoding or decoding)
+	#pragma HLS INTERFACE s_axilite port=stream_count   // size of data stream 
 	#pragma HLS INTERFACE axis port=din
 	#pragma HLS INTERFACE axis port=dout
 
-    din >> tmpA;
+    din >> tmpA;  //input data
 
     switch(selector)
-    {
+    {   
+        // case 0 is for encoding
         case 0:
             
             if (count_streams == 0){
-                final_char=0;
-                decNum = in_decimal;
+                
+                final_char=0;             
+                decNum = in_decimal;      //getting the ascii values of the word from the register
             }
 
                 addNum=0;
+
                 if(decimalCounter % 8 == 0){
+                    /*checking if the counter is 8 which means the process reached the 8th bit*/
                     lastDecimalVal = getDecimal(decNum);
-                    decNum /= 100;
-                    charIn=convert(lastDecimalVal);
+                    decNum /= 100;                       //to delete the processed ascii value and get the next one
+                    charIn=convert(lastDecimalVal);      //to find the binary of the next ascii value
                     
                 }
-                addNum=charIn%10;
-		        charIn=(int)charIn/10;
+                addNum=charIn%10;                   //LSB of charIn
+		        charIn=(int)charIn/10;              //deleting lsb and get the next bit(lsb)
 
+                //updating the input data according to addNum and lsb of the input data.
+                //if addNum is equal to 1 and input data is even , 1 will be added to input data which turns to odd
+                //otherwise no action needed
                 if(tmpA.data % 2 == 0 && addNum == 1){
+                    
                     tmpA.data += 1;
                     
-                }else if(tmpA.data % 2 != 0 && addNum == 0){
+                }
+                
+                //if addNum is equal to 0, input data is odd, 1 will be subtracted fro the input data which will turn it to even
+                //otherwise no action needed
+                else if(tmpA.data % 2 != 0 && addNum == 0){
                     tmpA.data -= 1;
                     
                 }
+
                 decimalCounter++;
 
             break;
 
+        //case 1 is for decoding
         case 1:
                 
-                
-                decrypt(tmpA.data);
+                decode(tmpA.data);    //getting decoded binary value bit by bit for every character
                 decimalCounter++;
                 if(decimalCounter == 8){
+                    //after processing 8 bits, the ascii value will be returned by the convertBinInt
                     decimalOut=decimalOut*100+convertBinInt(final_char);  
                     decimalCounter=0;
                     final_char=0;   
@@ -92,6 +80,7 @@ void pixel(apint &in_decimal,
 	count_streams++;
 
 	if (count_streams == stream_count){
+        //resetting variables
 		count_streams = 0;
         charIn=0;
         addNum=0;
@@ -105,17 +94,19 @@ void pixel(apint &in_decimal,
 	}
 
     if(count_streams == stream_count){
-	        tmpA.last = 1;
+        //setting TLAST signal to 1 
+	        tmpA.last = 1;              
+
 	    }
-	    tmpA.strb = 0xf;
 
 	    dout << tmpA;
-
 }
 
 
 long long convert(int n) {
-    /**/
+    /*
+    This function converts a decimal number to a Binary number and returns it
+    */
     long long bin = 0;
     int rem, i = 1, step = 1;
     while (n != 0) {
@@ -127,33 +118,40 @@ long long convert(int n) {
     return bin;
 }
 
-void decrypt(int data) {
-    /**/
-int bit;
-if(data % 2 == 0){
-   bit = 0;
-}else if(data % 2 != 0){
-    bit=1;
-}
-final_char= final_char*10+bit;
+void decode(int data) {
+    /*
+    get the binary value of the embedded ascii values by combining the LSBs.
+    */
+    int bit;
+    if(data % 2 == 0){
+    bit = 0;
+    }else if(data % 2 != 0){
+        bit=1;
+    }
+    final_char= final_char*10+bit;
 
 }
 
 int convertBinInt(long long n) {
-    /**/
-int dec = 0, i = 7, b=0,rem=0;
-    while (n != 0) {
-        b=pow(10,i);
-        rem = n / b;
-        n =n % b;
-        dec += rem * pow(2, 7-i);
-        --i;
-    }
+    /*
+    This function returns decimal value from a binary number
+    */
+    int dec = 0, i = 7, b=0,rem=0;
+
+        while (n != 0) {
+            b=pow(10,i);
+            rem = n / b;
+            n =n % b;
+            dec += rem * pow(2, 7-i);
+            --i;
+        }
     return dec;
 }
 
 int getDecimal(int n) {
-    /**/
+    /*
+    returns the last two digits (which represents one character) of the corresponding ascii values passed to this function.
+    */
     int num = 0;
     num = n % 100;
     return num;