setupPWM.S

.section .text
.align 2
.globl setupPWM

#include "memory_map.inc"
#include "gpio.inc"
#include "pwm.inc"

.equ PWM_COUNT_VALUE,  0x00000000
.equ PWM_CONFIG_VALUE, 0x0000360F # Corresponds to pwmscale=15, pwmzero=1, deglitch=1, enalways=1, enoneshot=1
.equ PWM_COMP_VALUE,   0x0000FFFF

.equ PWM_SCALE, 0x1
.equ PWM_FREQ, 0xFF
.equ PWM_DUTY, 0x32

setupPWM:
    addi sp, sp, -16            # allocate stack frame
    sw ra, 12(sp)               # store return address

    li t0, GPIO_CTRL_ADDR       # load control address
    li t1, LED_PIN              # load pin offset
    sw t1, GPIO_OUTPUT_EN(t0)   # Enable output on pin 16
    li t1, BOTH_PINS
    sw t1, GPIO_IOF_EN(t0)      # enables secondary actions for gpio
    sw t1, GPIO_IOF_SEL(t0)     # selects PWM Action

    li t2, PWM_CTRL2_ADDR       # load PWM Ctrl Address
    li t3, PWM_CONFIG_VALUE     # load PWM Config Address Value
    sw x0, PWM_CONFIG_REG(t2)   # zero pwm config area in memory
    sw t3, PWM_CONFIG_REG(t2)   # store pwm config into memory

    li t3, 0x0
    sw t3, PWM_SCALED_COUNT_REG(t2)

    li t3, 0x7F                 # testing of duty cycle.
    sw t3, PWM_CMP1_REG(t2)     # storing duty cycle value into cmp register. Determine this using datasheet to see what pin corresponds to which CTRL address and register
    # li t3, 0xFF                 # load cycle length
    # sw t3, PWM_CMP0_REG(t2)     # store cycle length in cmp re
    
    li t3, PWM_COUNT_VALUE      # load count value
    sw t3, PWM_COUNT_REG(t2)    # store count value into memory

    lw ra, 12(sp)               # restore return address
    addi sp,sp, 16              # deallocate stack
    ret