256 lines
7.2 KiB
C
256 lines
7.2 KiB
C
// See LICENSE for license details.
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#include <stdio.h>
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#include <stdlib.h>
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#include "platform.h"
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#include <string.h>
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#include "plic/plic_driver.h"
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#include "encoding.h"
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#include <unistd.h>
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#include "stdatomic.h"
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void reset_demo (void);
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// Structures for registering different interrupt handlers
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// for different parts of the application.
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typedef void (*function_ptr_t) (void);
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void no_interrupt_handler (void) {};
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function_ptr_t g_ext_interrupt_handlers[PLIC_NUM_INTERRUPTS];
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// Instance data for the PLIC.
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plic_instance_t g_plic;
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/*Entry Point for PLIC Interrupt Handler*/
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void handle_m_ext_interrupt(){
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plic_source int_num = PLIC_claim_interrupt(&g_plic);
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if ((int_num >=1 ) && (int_num < PLIC_NUM_INTERRUPTS)) {
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g_ext_interrupt_handlers[int_num]();
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}
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else {
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exit(1 + (uintptr_t) int_num);
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}
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PLIC_complete_interrupt(&g_plic, int_num);
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}
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/*Entry Point for Machine Timer Interrupt Handler*/
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void handle_m_time_interrupt(){
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clear_csr(mie, MIP_MTIP);
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// Reset the timer for 3s in the future.
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// This also clears the existing timer interrupt.
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volatile uint64_t * mtime = (uint64_t*) (CLINT_CTRL_ADDR + CLINT_MTIME);
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volatile uint64_t * mtimecmp = (uint64_t*) (CLINT_CTRL_ADDR + CLINT_MTIMECMP);
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uint64_t now = *mtime;
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uint64_t then = now + 2 * RTC_FREQ;
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*mtimecmp = then;
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// read the current value of the LEDS and invert them.
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uint32_t leds = GPIO_REG(GPIO_OUTPUT_VAL);
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GPIO_REG(GPIO_OUTPUT_VAL) ^= ((0x1 << RED_LED_OFFSET) |
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(0x1 << GREEN_LED_OFFSET) |
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(0x1 << BLUE_LED_OFFSET));
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// Re-enable the timer interrupt.
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set_csr(mie, MIP_MTIP);
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}
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const char * instructions_msg = " \
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\n\
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SIFIVE, INC.\n\
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\n\
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5555555555555555555555555\n\
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5555 5555\n\
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5555 5555\n\
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5555 5555\n\
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5555 5555555555555555555555\n\
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5555 555555555555555555555555\n\
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5555 5555\n\
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5555 5555\n\
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5555 5555\n\
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5555555555555555555555555555 55555\n\
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55555 555555555 55555\n\
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55555 55555 55555\n\
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55555 5 55555\n\
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55555 55555\n\
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55555 55555\n\
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55555 55555\n\
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55555 55555\n\
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55555 55555\n\
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555555555\n\
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55555\n\
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5\n\
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\n\
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SiFive E-Series Software Development Kit 'demo_gpio' program.\n\
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Every 2 second, the Timer Interrupt will invert the LEDs.\n\
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(Arty Dev Kit Only): Press Buttons 0, 1, 2 to Set the LEDs.\n\
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Pin 19 (HiFive1) or A5 (Arty Dev Kit) is being bit-banged\n\
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for GPIO speed demonstration.\n\
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\n\
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";
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void print_instructions() {
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write (STDOUT_FILENO, instructions_msg, strlen(instructions_msg));
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}
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#ifdef HAS_BOARD_BUTTONS
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void button_0_handler(void) {
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// Red LED on
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GPIO_REG(GPIO_OUTPUT_VAL) |= (0x1 << RED_LED_OFFSET);
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// Clear the GPIO Pending interrupt by writing 1.
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GPIO_REG(GPIO_RISE_IP) = (0x1 << BUTTON_0_OFFSET);
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};
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void button_1_handler(void) {
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// Green LED On
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GPIO_REG(GPIO_OUTPUT_VAL) |= (1 << GREEN_LED_OFFSET);
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// Clear the GPIO Pending interrupt by writing 1.
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GPIO_REG(GPIO_RISE_IP) = (0x1 << BUTTON_1_OFFSET);
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};
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void button_2_handler(void) {
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// Blue LED On
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GPIO_REG(GPIO_OUTPUT_VAL) |= (1 << BLUE_LED_OFFSET);
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GPIO_REG(GPIO_RISE_IP) = (0x1 << BUTTON_2_OFFSET);
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};
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#endif
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void reset_demo (){
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// Disable the machine & timer interrupts until setup is done.
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clear_csr(mie, MIP_MEIP);
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clear_csr(mie, MIP_MTIP);
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for (int ii = 0; ii < PLIC_NUM_INTERRUPTS; ii ++){
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g_ext_interrupt_handlers[ii] = no_interrupt_handler;
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}
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#ifdef HAS_BOARD_BUTTONS
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g_ext_interrupt_handlers[INT_DEVICE_BUTTON_0] = button_0_handler;
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g_ext_interrupt_handlers[INT_DEVICE_BUTTON_1] = button_1_handler;
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g_ext_interrupt_handlers[INT_DEVICE_BUTTON_2] = button_2_handler;
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#endif
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print_instructions();
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#ifdef HAS_BOARD_BUTTONS
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// Have to enable the interrupt both at the GPIO level,
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// and at the PLIC level.
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PLIC_enable_interrupt (&g_plic, INT_DEVICE_BUTTON_0);
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PLIC_enable_interrupt (&g_plic, INT_DEVICE_BUTTON_1);
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PLIC_enable_interrupt (&g_plic, INT_DEVICE_BUTTON_2);
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// Priority must be set > 0 to trigger the interrupt.
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PLIC_set_priority(&g_plic, INT_DEVICE_BUTTON_0, 1);
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PLIC_set_priority(&g_plic, INT_DEVICE_BUTTON_1, 1);
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PLIC_set_priority(&g_plic, INT_DEVICE_BUTTON_2, 1);
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GPIO_REG(GPIO_RISE_IE) |= (1 << BUTTON_0_OFFSET);
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GPIO_REG(GPIO_RISE_IE) |= (1 << BUTTON_1_OFFSET);
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GPIO_REG(GPIO_RISE_IE) |= (1 << BUTTON_2_OFFSET);
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#endif
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// Set the machine timer to go off in 3 seconds.
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// The
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volatile uint64_t * mtime = (uint64_t*) (CLINT_CTRL_ADDR + CLINT_MTIME);
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volatile uint64_t * mtimecmp = (uint64_t*) (CLINT_CTRL_ADDR + CLINT_MTIMECMP);
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uint64_t now = *mtime;
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uint64_t then = now + 2*RTC_FREQ;
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*mtimecmp = then;
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// Enable the Machine-External bit in MIE
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set_csr(mie, MIP_MEIP);
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// Enable the Machine-Timer bit in MIE
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set_csr(mie, MIP_MTIP);
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// Enable interrupts in general.
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set_csr(mstatus, MSTATUS_MIE);
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}
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int main(int argc, char **argv)
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{
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// Set up the GPIOs such that the LED GPIO
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// can be used as both Inputs and Outputs.
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#ifdef HAS_BOARD_BUTTONS
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GPIO_REG(GPIO_OUTPUT_EN) &= ~((0x1 << BUTTON_0_OFFSET) | (0x1 << BUTTON_1_OFFSET) | (0x1 << BUTTON_2_OFFSET));
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GPIO_REG(GPIO_PULLUP_EN) &= ~((0x1 << BUTTON_0_OFFSET) | (0x1 << BUTTON_1_OFFSET) | (0x1 << BUTTON_2_OFFSET));
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GPIO_REG(GPIO_INPUT_EN) |= ((0x1 << BUTTON_0_OFFSET) | (0x1 << BUTTON_1_OFFSET) | (0x1 << BUTTON_2_OFFSET));
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#endif
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GPIO_REG(GPIO_INPUT_EN) &= ~((0x1<< RED_LED_OFFSET) | (0x1<< GREEN_LED_OFFSET) | (0x1 << BLUE_LED_OFFSET)) ;
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GPIO_REG(GPIO_OUTPUT_EN) |= ((0x1<< RED_LED_OFFSET)| (0x1<< GREEN_LED_OFFSET) | (0x1 << BLUE_LED_OFFSET)) ;
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GPIO_REG(GPIO_OUTPUT_VAL) |= (0x1 << BLUE_LED_OFFSET) ;
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GPIO_REG(GPIO_OUTPUT_VAL) &= ~((0x1<< RED_LED_OFFSET) | (0x1<< GREEN_LED_OFFSET)) ;
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// For Bit-banging with Atomics demo.
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uint32_t bitbang_mask = 0;
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#ifdef _SIFIVE_HIFIVE1_H
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bitbang_mask = (1 << PIN_19_OFFSET);
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#else
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#ifdef _SIFIVE_COREPLEXIP_ARTY_H
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bitbang_mask = (0x1 << JA_0_OFFSET);
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#endif
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#endif
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GPIO_REG(GPIO_OUTPUT_EN) |= bitbang_mask;
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/**************************************************************************
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* Set up the PLIC
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*
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*************************************************************************/
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PLIC_init(&g_plic,
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PLIC_CTRL_ADDR,
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PLIC_NUM_INTERRUPTS,
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PLIC_NUM_PRIORITIES);
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reset_demo();
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/**************************************************************************
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* Demonstrate fast GPIO bit-banging.
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* One can bang it faster than this if you know
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* the entire OUTPUT_VAL that you want to write, but
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* Atomics give a quick way to control a single bit.
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*************************************************************************/
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// For Bit-banging with Atomics demo.
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uint32_t cnt=0;
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while(cnt<200){
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asm volatile ("wfi");
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printf("Finished run#%u\n", ++cnt);
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for(size_t i=0; i<100; ++i)
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atomic_fetch_xor_explicit(&GPIO_REG(GPIO_OUTPUT_VAL), bitbang_mask, memory_order_relaxed);
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}
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return 0;
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}
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