/** * Copyright (c) 2024 Raspberry Pi (Trading) Ltd. * * SPDX-License-Identifier: BSD-3-Clause */ #include <stdio.h> #include "pico/stdlib.h" #include "pico/multicore.h" #define ITERATIONS 100000 static int doorbell_counter; static int doorbell_exit; static uint32_t doorbell_irq_count; static bool exit_core0; // Handle the doorbell set from core0 void core1_doorbell_irq() { // Increment counter if (multicore_doorbell_is_set_current_core(doorbell_counter)) { doorbell_irq_count++; multicore_doorbell_clear_current_core(doorbell_counter); } // Are we finished? if (multicore_doorbell_is_set_current_core(doorbell_exit)) { multicore_doorbell_clear_current_core(doorbell_exit); exit_core0 = true; } } // code for core1 void core1_entry() { // Setup an interrupt handler for doorbells - there's actually only one for them all uint32_t irq = multicore_doorbell_irq_num(doorbell_counter); irq_set_exclusive_handler(irq, core1_doorbell_irq); irq_set_enabled(irq, true); // Keep going until the exit doorbell is set while (!exit_core0) { tight_loop_contents(); } printf("core1 is exiting\n"); multicore_doorbell_set_other_core(doorbell_exit); } int main() { stdio_init_all(); // claim doorbells doorbell_counter = multicore_doorbell_claim_unused((1 << NUM_CORES) - 1, true); doorbell_exit = multicore_doorbell_claim_unused((1 << NUM_CORES) - 1, true); // Make sure the exit doorbell is not set for this core multicore_doorbell_clear_current_core(doorbell_exit); // start core1 multicore_launch_core1(core1_entry); // set doorbell_counter as quickly as possible in a loop, we'll see how many times the other core irq sees it int count = ITERATIONS; while (count--) { multicore_doorbell_set_other_core(doorbell_counter); } // tell core 1 to exit multicore_doorbell_set_other_core(doorbell_exit); // wait for it to tell us it's done while(!multicore_doorbell_is_set_current_core(doorbell_exit)) { tight_loop_contents(); } stdio_flush(); // display results printf("Final doorbell irq count %u/%d (%d%%)\n", doorbell_irq_count, ITERATIONS, doorbell_irq_count * 100 / ITERATIONS); return 0; }

This firmware image was imported from the pico-examples repository. 


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