/*********************************************************************
    FileName:     	ADC.c
    Dependencies:	See #includes
    Processor:		PIC32MZ
    Hardware:		MainBrain MZ
    Complier:		XC32 4.40
    Author:		Larry Knight 2023
/*********************************************************************
 
    Software License Agreement:
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
 
    Description:
        System Clock = 200 - 250 MHz

    File Description:

    Change History:
 
/***********************************************************************/

#include <xc.h>
#include "MainBrain.h"

void ADC_init(void)
{
    /* Configure ADCCON1 */
    ADCCON1 = 0; // No ADCCON1 features are enabled including: Stop-in-Idle, turbo,
    // CVD mode, Fractional mode and scan trigger source.
    ADCCON1bits.SELRES = 3; // ADC7 resolution is 12 bits
    ADCCON1bits.STRGSRC = 1; // Select scan trigger.
    /* Configure ADCCON2 */
    ADCCON2bits.SAMC = 5; // ADC7 sampling time = 5 * TAD7
    ADCCON2bits.ADCDIV = 1; // ADC7 clock freq is half of control clock = TAD7
    /* Initialize warm up time register */
    ADCANCON = 0;
    ADCANCONbits.WKUPCLKCNT = 5; // Wakeup exponent = 32 * TADx
    /* Clock setting */
    ADCCON3bits.ADCSEL = 0; // Select input clock source
    ADCCON3bits.CONCLKDIV = 1; // Control clock frequency is half of input clock
    ADCCON3bits.VREFSEL = 0; // Select AVDD and AVSS as reference source
    ADC0TIMEbits.ADCDIV = 1; // ADC0 clock frequency is half of control clock = TAD0
    ADC0TIMEbits.SAMC = 5; // ADC0 sampling time = 5 * TAD0
    ADC0TIMEbits.SELRES = 3; // ADC0 resolution is 12 bits
    /* Select analog input for ADC modules, no presync trigger, not sync sampling */
    ADCTRGMODEbits.SH0ALT = 0; // ADC0 = AN0
    /* Select ADC input mode */
    ADCIMCON1bits.SIGN0 = 0; // unsigned data format
    ADCIMCON1bits.DIFF0 = 0; // Single ended mode
    ADCIMCON1bits.SIGN6 = 0; // unsigned data format
    ADCIMCON1bits.DIFF6 = 0; // Single ended mode
    /* Configure ADCGIRQENx */
    ADCGIRQEN1 = 0; // No interrupts are used.
    ADCGIRQEN2 = 0;
    /* Configure ADCCSSx */
    ADCCSS1 = 0; // Clear all bits
    ADCCSS2 = 0;
    ADCCSS1bits.CSS0 = 1; // AN0 (Class 1) set for scan
    ADCCSS1bits.CSS6 = 1; // AN6 (Class 2) set for scan

    /* Configure ADCCMPCONx */
    ADCCMPCON1 = 0; // No digital comparators are used. Setting the ADCCMPCONx
    ADCCMPCON2 = 0; // register to '0' ensures that the comparator is disabled.
    ADCCMPCON3 = 0; // Other registers are ?don't care?.
    ADCCMPCON4 = 0;
    ADCCMPCON5 = 0;
    ADCCMPCON6 = 0;
    /* Configure ADCFLTRx */
    ADCFLTR1 = 0; // No oversampling filters are used.
    ADCFLTR2 = 0;
    ADCFLTR3 = 0;
    ADCFLTR4 = 0;
    ADCFLTR5 = 0;
    ADCFLTR6 = 0;

    /* Set up the trigger sources */
    ADCTRG1bits.TRGSRC0 = 3; // Set AN0 (Class 1) to trigger from scan source
    ADCTRG2bits.TRGSRC6 = 3; // Set AN6 (Class 2) to trigger from scan source

    /* Early interrupt */
    ADCEIEN1 = 0; // No early interrupt
    ADCEIEN2 = 0;
    /* Turn the ADC on */
    ADCCON1bits.ON = 1;
    /* Wait for voltage reference to be stable */
    while(!ADCCON2bits.BGVRRDY); // Wait until the reference voltage is ready
    while(ADCCON2bits.REFFLT); // Wait if there is a fault with the reference voltage
    /* Enable clock to analog circuit */
    ADCANCONbits.ANEN0 = 1; // Enable the clock to analog bias ADC0
    ADCANCONbits.ANEN7 = 1; // Enable, ADC7
    /* Wait for ADC to be ready */
    while(!ADCANCONbits.WKRDY0); // Wait until ADC0 is ready
    while(!ADCANCONbits.WKRDY7); // Wait until ADC7 is ready
    /* Enable the ADC module */
    ADCCON3bits.DIGEN0 = 1; // Enable ADC0
    ADCCON3bits.DIGEN7 = 1; // Enable ADC7
}