Srivishnu Alvakonda / Mbed 2 deprecated Module1

Module 1 ECEN 5803 Project 1 Submitted by 1. Rahul Yamasani 2. Srivishnuj Alvakonda

Dependencies:   mbed

main.cpp@0:a7b003d6eac1, 2017-10-12 (annotated)

Committer:
sral4054
Date:
Thu Oct 12 03:22:25 2017 +0000
Revision:
0:a7b003d6eac1
Module 1 ECEN 5803 Project 1; ; Submitted by; 1. Rahul Yamasani; 2. Srivishnuj Alvakonda;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
sral4054 0:a7b003d6eac1 1 #include "mbed.h"
sral4054 0:a7b003d6eac1 2 Serial pc(USBTX, USBRX); //serial channel over HDK USB interface
sral4054 0:a7b003d6eac1 3 Timer timer;
sral4054 0:a7b003d6eac1 4 /************************************************************************//**
sral4054 0:a7b003d6eac1 5 * \file main.c
sral4054 0:a7b003d6eac1 6 * \brief LAB EXERCISE 5.2 - SQUARE ROOT APPROXIMATION
sral4054 0:a7b003d6eac1 7 *
sral4054 0:a7b003d6eac1 8 * Write an assembly code subroutine to approximate the square root of an
sral4054 0:a7b003d6eac1 9 * argument using the bisection method. All math is done with integers, so the
sral4054 0:a7b003d6eac1 10 * resulting square root will also be an integer
sral4054 0:a7b003d6eac1 11 ******************************************************************************
sral4054 0:a7b003d6eac1 12 * GOOD LUCK!
sral4054 0:a7b003d6eac1 13 ****************************************************************************/
sral4054 0:a7b003d6eac1 14
sral4054 0:a7b003d6eac1 15 #include "stdint.h"
sral4054 0:a7b003d6eac1 16
sral4054 0:a7b003d6eac1 17
sral4054 0:a7b003d6eac1 18 /** @cond DO_NOT_INCLUDE_WITH_DOXYGEN */
sral4054 0:a7b003d6eac1 19 #include "string.h"
sral4054 0:a7b003d6eac1 20 /** @endcond */
sral4054 0:a7b003d6eac1 21
sral4054 0:a7b003d6eac1 22 /**
sral4054 0:a7b003d6eac1 23 * @brief 5863 Write a brief description of the function here
sral4054 0:a7b003d6eac1 24 *
sral4054 0:a7b003d6eac1 25 * Detailed description of the function after one line gap
sral4054 0:a7b003d6eac1 26 *
sral4054 0:a7b003d6eac1 27 * @note You can also add a note this way
sral4054 0:a7b003d6eac1 28 *
sral4054 0:a7b003d6eac1 29 * @param[in]
sral4054 0:a7b003d6eac1 30 * You can also start writing on a new line.
sral4054 0:a7b003d6eac1 31 * And continue on the next line. This is how you describe an input parameter
sral4054 0:a7b003d6eac1 32 *
sral4054 0:a7b003d6eac1 33 * @return
sral4054 0:a7b003d6eac1 34 * This is how you describe the return value
sral4054 0:a7b003d6eac1 35 *
sral4054 0:a7b003d6eac1 36 */
sral4054 0:a7b003d6eac1 37
sral4054 0:a7b003d6eac1 38 __asm int my_sqrt(int x){
sral4054 0:a7b003d6eac1 39
sral4054 0:a7b003d6eac1 40
sral4054 0:a7b003d6eac1 41 PUSH {R4-R7} ;
sral4054 0:a7b003d6eac1 42 LDR R1, =0 ;done = 0
sral4054 0:a7b003d6eac1 43 LDR R7, =0 ;a=0
sral4054 0:a7b003d6eac1 44 LDR R2, =0xFFFF ;b=2^31 -1
sral4054 0:a7b003d6eac1 45 LDR R3, =0xFFFFFFFF ;c=-1
sral4054 0:a7b003d6eac1 46 DO_WHILE
sral4054 0:a7b003d6eac1 47 MOV R4, R3 ;c_old = c HERE R4 is being considered as c_old
sral4054 0:a7b003d6eac1 48 ADDS R5, R2, R7 ;R5 = a+b
sral4054 0:a7b003d6eac1 49 ASRS R5, R5, #1 ;R5 >> 1 which is nothing but (a+b/2)
sral4054 0:a7b003d6eac1 50 MOV R3, R5 ;c = (a+b)/2
sral4054 0:a7b003d6eac1 51 MOV R6,R3
sral4054 0:a7b003d6eac1 52 MULS R6, R3, R6 ;R6 = c*c
sral4054 0:a7b003d6eac1 53 CMP R6,R0 ;compare c*c and x (input integer)
sral4054 0:a7b003d6eac1 54 BEQ DONE
sral4054 0:a7b003d6eac1 55 BLT LESS_THAN
sral4054 0:a7b003d6eac1 56 MOV R2, R3 ;setting b=c
sral4054 0:a7b003d6eac1 57 B FINAL
sral4054 0:a7b003d6eac1 58
sral4054 0:a7b003d6eac1 59 LESS_THAN
sral4054 0:a7b003d6eac1 60 MOV R7,R3 ;setting a=c
sral4054 0:a7b003d6eac1 61 B FINAL
sral4054 0:a7b003d6eac1 62
sral4054 0:a7b003d6eac1 63
sral4054 0:a7b003d6eac1 64 DONE
sral4054 0:a7b003d6eac1 65 LDR R1, =1 ;setting done = 1
sral4054 0:a7b003d6eac1 66 B FINAL ;return C
sral4054 0:a7b003d6eac1 67
sral4054 0:a7b003d6eac1 68
sral4054 0:a7b003d6eac1 69 FINAL
sral4054 0:a7b003d6eac1 70 CMP R1, #1 ;compare done = 1
sral4054 0:a7b003d6eac1 71 BEQ END
sral4054 0:a7b003d6eac1 72 BNE COMPARE
sral4054 0:a7b003d6eac1 73
sral4054 0:a7b003d6eac1 74
sral4054 0:a7b003d6eac1 75 COMPARE
sral4054 0:a7b003d6eac1 76 CMP R4, R3 ;compare c_old and c
sral4054 0:a7b003d6eac1 77 BNE DO_WHILE
sral4054 0:a7b003d6eac1 78 BEQ END
sral4054 0:a7b003d6eac1 79
sral4054 0:a7b003d6eac1 80
sral4054 0:a7b003d6eac1 81 END
sral4054 0:a7b003d6eac1 82 MOV R0, R3
sral4054 0:a7b003d6eac1 83 POP {R4-R7}
sral4054 0:a7b003d6eac1 84 BX LR
sral4054 0:a7b003d6eac1 85 }
sral4054 0:a7b003d6eac1 86
sral4054 0:a7b003d6eac1 87 void printCpuCycles(double readValue, int number, int sqrt)
sral4054 0:a7b003d6eac1 88 {
sral4054 0:a7b003d6eac1 89 double cpuCycles = 0;
sral4054 0:a7b003d6eac1 90
sral4054 0:a7b003d6eac1 91 cpuCycles = (readValue * 48000000); // read value * frequqncy of clock
sral4054 0:a7b003d6eac1 92 pc.printf("Sqrt of %d using bisection menthod is %d \n\r", number, sqrt);
sral4054 0:a7b003d6eac1 93 pc.printf("Total time of execution for sqrt of(%d)is %f \n\r", number, readValue);
sral4054 0:a7b003d6eac1 94 pc.printf("Number of CPU cycles for sqrt(%d): %d\n\r\n\r", number, (int)cpuCycles);
sral4054 0:a7b003d6eac1 95 }
sral4054 0:a7b003d6eac1 96 /*----------------------------------------------------------------------------
sral4054 0:a7b003d6eac1 97 MAIN function
sral4054 0:a7b003d6eac1 98 *----------------------------------------------------------------------------*/
sral4054 0:a7b003d6eac1 99 /**
sral4054 0:a7b003d6eac1 100 * @brief Main function
sral4054 0:a7b003d6eac1 101 *
sral4054 0:a7b003d6eac1 102 * Detailed description of the main
sral4054 0:a7b003d6eac1 103 */
sral4054 0:a7b003d6eac1 104 int main(void){
sral4054 0:a7b003d6eac1 105
sral4054 0:a7b003d6eac1 106 volatile int r, j=0;
sral4054 0:a7b003d6eac1 107
sral4054 0:a7b003d6eac1 108 double timer_read = 0.0;
sral4054 0:a7b003d6eac1 109 double sum = 0;
sral4054 0:a7b003d6eac1 110
sral4054 0:a7b003d6eac1 111 pc.printf("/*----------------------------------------------------------------------------*/\r\n\r\n");
sral4054 0:a7b003d6eac1 112 pc.printf("Frequency of KL25Z (ARM Cortex M0+): 48 MHZ\n\r\n\r");
sral4054 0:a7b003d6eac1 113
sral4054 0:a7b003d6eac1 114 timer.start();
sral4054 0:a7b003d6eac1 115
sral4054 0:a7b003d6eac1 116 timer.reset();
sral4054 0:a7b003d6eac1 117 r = my_sqrt(2); // should be 1
sral4054 0:a7b003d6eac1 118 timer_read = timer.read();
sral4054 0:a7b003d6eac1 119 printCpuCycles(timer_read, 2, r);
sral4054 0:a7b003d6eac1 120 sum = sum + timer_read;
sral4054 0:a7b003d6eac1 121 timer.reset();
sral4054 0:a7b003d6eac1 122
sral4054 0:a7b003d6eac1 123
sral4054 0:a7b003d6eac1 124
sral4054 0:a7b003d6eac1 125 r = my_sqrt(4); // should be 2
sral4054 0:a7b003d6eac1 126 timer_read = timer.read();
sral4054 0:a7b003d6eac1 127 printCpuCycles(timer_read, 4, r);
sral4054 0:a7b003d6eac1 128 sum = sum + timer_read;
sral4054 0:a7b003d6eac1 129 timer.reset();
sral4054 0:a7b003d6eac1 130
sral4054 0:a7b003d6eac1 131
sral4054 0:a7b003d6eac1 132
sral4054 0:a7b003d6eac1 133 r = my_sqrt(22); // should be 4
sral4054 0:a7b003d6eac1 134 timer_read = timer.read();
sral4054 0:a7b003d6eac1 135 printCpuCycles(timer_read, 22, r);
sral4054 0:a7b003d6eac1 136 sum = sum + timer_read;
sral4054 0:a7b003d6eac1 137 timer.reset();
sral4054 0:a7b003d6eac1 138
sral4054 0:a7b003d6eac1 139 r = my_sqrt(121); // should be 11
sral4054 0:a7b003d6eac1 140 timer_read = timer.read();
sral4054 0:a7b003d6eac1 141 printCpuCycles(timer_read, 121, r);
sral4054 0:a7b003d6eac1 142 sum = sum + timer_read;
sral4054 0:a7b003d6eac1 143
sral4054 0:a7b003d6eac1 144 pc.printf("Total time of operation: %f\n\r\n\r", sum);
sral4054 0:a7b003d6eac1 145 sum = sum * 48000000;
sral4054 0:a7b003d6eac1 146 pc.printf("CPU cycles: %d\n\r\n\r", (int)(sum));
sral4054 0:a7b003d6eac1 147
sral4054 0:a7b003d6eac1 148 pc.printf("/*----------------------------------------------------------------------------*/\r\n\r\n");
sral4054 0:a7b003d6eac1 149
sral4054 0:a7b003d6eac1 150 }
sral4054 0:a7b003d6eac1 151
sral4054 0:a7b003d6eac1 152 // *******************************ARM University Program Copyright © ARM Ltd 2014*************************************/
sral4054 0:a7b003d6eac1 153