Subversion Repositories neo430

// #################################################################################################
// #  < neo430_exirqt.c - External interrupts controler driver functions >                         #
// # ********************************************************************************************* #
// # BSD 3-Clause License                                                                          #
// #                                                                                               #
// # Copyright (c) 2020, Stephan Nolting. All rights reserved.                                     #
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// #    permission.                                                                                #
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// # ********************************************************************************************* #
// # The NEO430 Processor - https://github.com/stnolting/neo430                                    #
// #################################################################################################
 
#include "neo430.h"
#include "neo430_exirq.h"
 
// Private variables
static uint16_t neo430_exirq_vectors[8] __attribute__((unused)); // do not ouput a warning when this variable is unused
 
// Private function prototypes
static void __attribute__((__interrupt__)) _exirq_irq_handler_(void);
 
 
/* ------------------------------------------------------------
 * INFO Enable external interrupts controller
 * ------------------------------------------------------------ */
void neo430_exirq_enable(void) {
 
  EXIRQ_CT |= (1<<EXIRQ_CT_EN);
}
 
 
/* ------------------------------------------------------------
 * INFO Disable external interrupts controller
 * ------------------------------------------------------------ */
void neo430_exirq_disable(void) {
 
  EXIRQ_CT &= ~(1<<EXIRQ_CT_EN);
}
 
 
/* ------------------------------------------------------------
 * INFO Configure external interrupts controller
 * PARAM Struct containing the handler functions addresses and the channel enable bits
 * ------------------------------------------------------------ */
void neo430_exirq_config(struct neo430_exirq_config_t config) {
 
  // reset controller
  EXIRQ_CT = 0;
 
  // get handler function address
  neo430_exirq_vectors[0] = config.address[0];
  neo430_exirq_vectors[1] = config.address[1];
  neo430_exirq_vectors[2] = config.address[2];
  neo430_exirq_vectors[3] = config.address[3];
  neo430_exirq_vectors[4] = config.address[4];
  neo430_exirq_vectors[5] = config.address[5];
  neo430_exirq_vectors[6] = config.address[6];
  neo430_exirq_vectors[7] = config.address[7];
 
  // set correct CPU external interrupts request handler address
  IRQVEC_EXT = (uint16_t)(&_exirq_irq_handler_);
 
  // configure channel enables
  uint16_t enable = (uint16_t)config.enable;
  EXIRQ_CT = (enable<<EXIRQ_CT_IRQ0_EN);
}
 
 
/* ------------------------------------------------------------
 * INFO Trigger IRQ channel by software
 * PARAM id (0..7) indicating which (ENABLED!) channel shall be triggered
 * ------------------------------------------------------------ */
void neo430_exirq_sw_irq(uint8_t id) {
 
  uint16_t irq_sel = (uint16_t)(id & 7);
 
  // apply sw irq enable bit and according irq select
  uint16_t exirq_ctrl = EXIRQ_CT & (~(0b111 << EXIRQ_CT_SEL0)); // clear IRQ src output
  EXIRQ_CT = exirq_ctrl | (1<<EXIRQ_CT_SW_IRQ) | (irq_sel<<EXIRQ_CT_SEL0); // set dst. IRQ and set SW_IRQ flag
}
 
 
/* ------------------------------------------------------------
 * INFO Actual external interrupts controller IRQ handler
 * INFO This function is automatically installed
 * ------------------------------------------------------------ */
static void __attribute__((__interrupt__)) _exirq_irq_handler_(void) {
 
  register uint16_t exirq_ctrl = EXIRQ_CT;
 
  EXIRQ_CT = exirq_ctrl | (1 << EXIRQ_CT_ACK_IRQ); // ACK IRQ
 
  register uint16_t src = exirq_ctrl & (0b111 << EXIRQ_CT_SEL0); // get IRQ source
  register uint16_t adr = neo430_exirq_vectors[src];
  asm volatile ("call %0" : : "r" (adr)); // call according handler
}