circuitpython/ports/pic16bit/board.c

170 lines
4.1 KiB
C
Raw Normal View History

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2015 Damien P. George
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <p33Fxxxx.h>
#include "board.h"
/********************************************************************/
// CPU
void cpu_init(void) {
// set oscillator to operate at 40MHz
// Fosc = Fin*M/(N1*N2), Fcy = Fosc/2
// Fosc = 7.37M*40/(2*2) = 80Mhz for 7.37M input clock
PLLFBD = 41; // M=39
CLKDIVbits.PLLPOST = 0; // N1=2
CLKDIVbits.PLLPRE = 0; // N2=2
OSCTUN = 0;
// initiate clock switch to FRC with PLL
__builtin_write_OSCCONH(0x01);
__builtin_write_OSCCONL(0x01);
// wait for clock switch to occur
while (OSCCONbits.COSC != 0x01) {
}
while (!OSCCONbits.LOCK) {
}
}
/********************************************************************/
// LEDs
#define RED_LED_TRIS _TRISC15
#define YELLOW_LED_TRIS _TRISC13
#define GREEN_LED_TRIS _TRISC14
#define RED_LED _LATC15
#define YELLOW_LED _LATC13
#define GREEN_LED _LATC14
#define LED_ON (0)
#define LED_OFF (1)
void led_init(void) {
// set led GPIO as outputs
RED_LED_TRIS = 0;
YELLOW_LED_TRIS = 0;
GREEN_LED_TRIS = 0;
// turn off the LEDs
RED_LED = LED_OFF;
YELLOW_LED = LED_OFF;
GREEN_LED = LED_OFF;
}
void led_state(int led, int state) {
int val = state ? LED_ON : LED_OFF;
switch (led) {
case 1:
RED_LED = val;
break;
case 2:
YELLOW_LED = val;
break;
case 3:
GREEN_LED = val;
break;
}
}
void led_toggle(int led) {
switch (led) {
case 1:
RED_LED ^= 1;
break;
case 2:
YELLOW_LED ^= 1;
break;
case 3:
GREEN_LED ^= 1;
break;
}
}
/********************************************************************/
// switches
#define SWITCH_S1_TRIS _TRISD8
#define SWITCH_S2_TRIS _TRISD9
#define SWITCH_S1 _RD8
#define SWITCH_S2 _RD9
void switch_init(void) {
// set switch GPIO as inputs
SWITCH_S1_TRIS = 1;
SWITCH_S2_TRIS = 1;
}
int switch_get(int sw) {
int val = 1;
switch (sw) {
case 1:
val = SWITCH_S1;
break;
case 2:
val = SWITCH_S2;
break;
}
return val == 0;
}
/********************************************************************/
// UART
/*
// TODO need an irq
void uart_rx_irq(void) {
if (c == interrupt_char) {
MP_STATE_VM(mp_pending_exception) = MP_STATE_PORT(keyboard_interrupt_obj);
}
}
*/
void uart_init(void) {
// baudrate = F_CY / 16 (uxbrg + 1)
// F_CY = 40MHz for us
UART1.uxbrg = 64; // 38400 baud
UART1.uxmode = 1 << 15; // UARTEN
UART1.uxsta = 1 << 10; // UTXEN
}
int uart_rx_any(void) {
return UART1.uxsta & 1; // URXDA
}
int uart_rx_char(void) {
return UART1.uxrxreg;
}
void uart_tx_char(int chr) {
while (UART1.uxsta & (1 << 9)) {
// tx fifo is full
}
UART1.uxtxreg = chr;
}