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I have some 'bare metal' code for setting up timer interrupts on the Arduino R4 Minima that I share below. It is quite generic and can also be used to setup pin change interrupts on most pins. I have found i quite useful and maybe this can be of help. The code sets up a counter overflow interrupt on GPT7 and installs an ISR that increments a counter once every 1 msec. The pin change interrupt ISR stops the GPT on a falling edge on D2. /********************************************************************** * Arduino UNO R4 Minima * Renesas RA4M1 (Arm Cortex-M4), R7FA4M1AB3CFM * MCU: R7FA4M1AB3CFM (LQFP64) * *********************************************************************/ static const int dly_msec = 500; static const IRQn_Type IRQn_OVF7 = IRQn_Type(16); // Valid range is [0,31] but don't use low numbers static const IRQn_Type IRQn_PCHGD2 = IRQn_Type(17); // Valid range is [0,31] but don't use low numbers static volatile int t7_cnt = 0; static int cnt = 0; //********************************************************************* void gpt7_ovf_isr() { // Clear interrupt flag R_ICU->IELSR_b[IRQn_OVF7].IR = 0; // Increment GPT7 counter t7_cnt++; } //********************************************************************* void pin_change_isr() { // Clear interrupt flag R_ICU->IELSR_b[IRQn_PCHGD2].IR = 0; // Stop GPT7 R_GPT7->GTCR_b.CST = 0; // On-board LED off digitalWrite(LED_BUILTIN, LOW); // Clear GPT7 counter t7_cnt = 0; } //********************************************************************* void setup_pin_change_interrupt() { // Pin change interrupt on pin D3/P104/IRQ1 // See chapter 1.7 Pin Lists for LQFP64 // Setup I/O pin P104 //R_PFS->PORT[1].PIN[4].PmnPFS_b.PODR = 0b0; // Low //R_PFS->PORT[1].PIN[4].PmnPFS_b.PDR = 0b0; // Input //R_PFS->PORT[1].PIN[4].PmnPFS_b.PMR = 0b0; // I/O pin R_PFS->PORT[1].PIN[4].PmnPFS_b.PCR = 0b1; // Enable pull-up R_PFS->PORT[1].PIN[4].PmnPFS_b.EOFR = 0b10; // Event on falling edge // Tables 19.5 and onwards R_PFS->PORT[1].PIN[4].PmnPFS_b.ISEL = 0b1; // Use as IRQn pin // The Interrupt Controller Unit (ICU) controls which event signals are linked to the Nested Vector Interrupt Controller // (NVIC), Data Transfer Control (DTC), and Direct Memory Access Controller (DMAC) modules. // See Table 13.3 Interrupt vector table // See Table 13.4 Event table // There are 47 exceptions that can be connected to events, Table 13.3 // The first 16 exceptions are fixed NMIs, the first user definable // exception is number 16 = interrupt number 0, valid interrupt numbers are [0, 31] // To assign which event that triggers which interrupt, set: // R_ICU->IELSR[IRQn] = EVENTn; // LQFP64 D2/P104/IRQ1, Table 13.4, table 18.3, table 19.5 // Select the IRQn_PCHG2 interrupt to be triggered by the pin change event IRQ1 (2) R_ICU->IELSR_b[IRQn_PCHGD2].IELS = ELC_EVENT_ICU_IRQ1; // Install the ISR in the IRQn_PCHGD2 interrupt vector element NVIC_SetVector(IRQn_PCHGD2, (uint32_t)pin_change_isr); // Set a suitable interrupt priority NVIC_SetPriority(IRQn_PCHGD2, 12); // Enable the interrupt NVIC_EnableIRQ(IRQn_PCHGD2); } //********************************************************************* void setup_gpt7() { // Enable peripherals // RA4M1 User’s Manual: Hardware, chapter 10.2.5, Module stop control register D //R_MSTP->MSTPCRD_b.MSTPD5 = 0; // Enable 32-bit GPT321 to GPT320, GPT0, GPT1 R_MSTP->MSTPCRD_b.MSTPD6 = 0; // Enable 16-bit GPT167 to GPT162, GPT2-GPT7 // The Interrupt Controller Unit (ICU) controls which event signals are linked to the Nested Vector Interrupt Controller // (NVIC), Data Transfer Control (DTC), and Direct Memory Access Controller (DMAC) modules. // See Table 13.3 Interrupt vector table // See Table 13.4 Event table // There are 47 exceptions that can be connected to events, Table 13.3 // The first 16 exceptions are fixed NMIs, the first user definable // exception is number 16 = interrupt number 0, valid interrupt numbers are [0, 31] // To assign which event that triggers which interrupt, set: // R_ICU->IELSR[IRQn] = EVENTn; // Select the IRQn_OVF7 interrupt to be triggered by the GPT7 overflow event (0x95 = 149, Table 13.4) R_ICU->IELSR_b[IRQn_OVF7].IELS = ELC_EVENT_GPT7_COUNTER_OVERFLOW; // Install the ISR in the IRQn_OVF7 interrupt vector element NVIC_SetVector(IRQn_OVF7, (uint32_t)gpt7_ovf_isr); // Set a suitable interrupt priority NVIC_SetPriority(IRQn_OVF7, 12); // Enable the interrupt NVIC_EnableIRQ(IRQn_OVF7); // Timer counter R_GPT7->GTCNT = 0; // Timer period, pwm period R_GPT7->GTPR = 48000 - 1; // OVF interrupt every 1000 usec at PS=1 and f_MCU 48 MHz // Zero timer control register R_GPT7->GTCR = 0; // Timer pre-scaler R_GPT7->GTCR &= ~(0b111 << 24); // Clear bits, PS = 1 //R_GPT7->GTCR |= (0b011 << 24); // PS = 64, 64/48 = 4/3 usec per TCLK //R_GPT7->GTCR |= (0b101 << 24); // PS = 1024 // Start timer R_GPT7->GTCR_b.CST = 1; } //********************************************************************* void setup() { Serial.begin(9600); //Serial.dtr(); // Only needed for Arduino R4 Minima pinMode(LED_BUILTIN, OUTPUT); digitalWrite(LED_BUILTIN, LOW); setup_gpt7(); setup_pin_change_interrupt(); } //********************************************************************* void loop() { for (t7_cnt = 0; t7_cnt < dly_msec;) {} digitalWrite(LED_BUILTIN, HIGH); for (t7_cnt = 0; t7_cnt < dly_msec;) {} digitalWrite(LED_BUILTIN, LOW); cnt++; Serial.print(" Counter value = "); Serial.println(cnt); } (责任编辑：) |