Fix-timer-sdk

sw/applications/example_timer_sdk/main.c

@@ -3,8 +3,8 @@
 // SPDX-License-Identifier: Apache-2.0 WITH SHL-2.1
 //
 // File: example_timer_sdk.c
-// Author: Juan Sapriza
-// Date: 15/07/2024
+// Author: Juan Sapriza, Francesco Poluzzi
+// Date: 23/07/2024
 // Description: Example application to test the Timer SDK. Will count the time to execute a few short tasks.
 
 #include <stdint.h>
@@ -15,7 +15,7 @@
 
 /* By default, printfs are activated for FPGA and disabled for simulation. */
 #define PRINTF_IN_FPGA  1
-#define PRINTF_IN_SIM   0
+#define PRINTF_IN_SIM   1
 
 #if TARGET_SIM && PRINTF_IN_SIM
         #define PRINTF(fmt, ...)    printf(fmt, ## __VA_ARGS__)
@@ -25,32 +25,59 @@
     #define PRINTF(...)
 #endif
 
+void __attribute__((aligned(4), interrupt)) handler_irq_timer(void) {
+    timer_arm_stop();
+    timer_irq_clear();
+    return;   
+}
+
 int main(){
-    uint8_t i = 0;
-    uint32_t cpu_cycles;
+    uint32_t i = 0;
+    uint32_t timer_cycles;
 
-    timer_init();               // Init the timer SDK
+    timer_init();               // Init the timer SDK for clock cycles
     timer_start();              // Start counting the time
-    cpu_cycles = timer_stop();  // Stop counting the time
-    PRINTF("0 NOPs:\t%d cc\n\r", cpu_cycles );
+    timer_cycles = timer_stop();  // Stop counting the time
+    PRINTF("0 NOPs:\t%d cc\n\r", timer_cycles );
 
-    timer_start();              
+    timer_start();     
     asm volatile ("nop");
-    cpu_cycles = timer_stop();  
-    PRINTF("1 NOP:\t%d cc\n\r", cpu_cycles );
+    timer_cycles = timer_stop();  
+    PRINTF("1 NOP:\t%d cc\n\r", timer_cycles );
 
     timer_start();              
     asm volatile ("nop");
     asm volatile ("nop");
-    cpu_cycles = timer_stop();  
-    PRINTF("2 NOPs:\t%d cc\n\r", cpu_cycles );
+    timer_cycles = timer_stop();  
+    PRINTF("2 NOPs:\t%d cc\n\r", timer_cycles );
 
     timer_start();              
     asm volatile ("nop");
     asm volatile ("nop");
     asm volatile ("nop");
-    cpu_cycles = timer_stop();  
-    PRINTF("3 NOPs:\t%d cc\n\r", cpu_cycles );
-
+    timer_cycles = timer_stop();  
+    PRINTF("3 NOPs:\t%d cc\n\r", timer_cycles );
+
+    enable_timer_interrupt();   // Enable the timer machine-level interrupt
+
+    timer_init();
+    timer_irq_enable();
+    timer_arm_start(1000);
+    timer_start();              
+    asm volatile ("wfi");       // Wait for interrupt
+    timer_cycles = timer_stop();  
+    PRINTF("wait ARM timer 1000 (%d)\n\r", timer_cycles );
+
+    timer_init_us();           // Init the timer SDK for microseconds
+    timer_start(); 
+    for(i = 0; i < 1000; i++){
+        asm volatile ("nop");
+    }
+    PRINTF("Microseconds for 1000 NOPs:\t%d μs\n\r", timer_stop() );
+
+    PRINTF("Wait 5 seconds\n\r");
+    timer_wait_ms(5000);       // Wait for 5 seconds
+    PRINTF("Done\n\r");
+
     return EXIT_SUCCESS;
-}
+}

sw/device/lib/sdk/timer/timer_sdk.c

@@ -3,14 +3,16 @@
 // SPDX-License-Identifier: Apache-2.0 WITH SHL-2.1
 //
 // File: timer_sdk.c
-// Author: Michele Caon
-// Date: 31/07/2023
+// Author: Michele Caon, Francesco Poluzzi
+// Date: 23/07/2024
 // Description: Timer functions
 
 #include <stdint.h>
 
 #include "timer_sdk.h"
 #include "csr.h"
+#include "soc_ctrl.h"
+
 
 /******************************/
 /* ---- GLOBAL VARIABLES ---- */
@@ -33,27 +35,40 @@ mmio_region_t timer_base = {
 
 rv_timer_tick_params_t tick_params;
 
+
 /*************************************/
 /* ---- FUNCTION IMPLEMENTATION ---- */
 /*************************************/
 
-// Initialize the hardware timer
-void hw_timer_init()
-{
-    // Initialize the timer
-    rv_timer_init(timer_base, timer_cfg, &timer);
-    rv_timer_approximate_tick_params(REFERENCE_CLOCK_Hz, REFERENCE_CLOCK_Hz, &tick_params);
-    rv_timer_set_tick_params(&timer, 0, tick_params);
-    rv_timer_counter_set_enabled(&timer, 0, kRvTimerEnabled);
-}
-
 uint32_t hw_timer_get_cycles()
 {
     uint64_t cycle_count;
     rv_timer_counter_read(&timer, 0, &cycle_count);
     return (uint32_t)cycle_count;
 }
 
+void timer_irq_enable()
+{
+  rv_timer_irq_enable(&timer, 0, 0, kRvTimerEnabled);
+}
+
+void timer_irq_clear()
+{
+  rv_timer_irq_clear(&timer, 0, 0);
+}
+
+
+void timer_arm_start(uint32_t threshold)
+{
+    rv_timer_arm(&timer, 0, 0, threshold);
+    rv_timer_counter_set_enabled(&timer, 0, kRvTimerEnabled);
+}
+
+void timer_arm_stop()
+{
+    rv_timer_counter_set_enabled(&timer, 0, kRvTimerDisabled);
+}
+
 void hw_timer_start()
 {
     hw_timer_value = -hw_timer_get_cycles();
@@ -68,6 +83,50 @@ uint32_t hw_timer_stop()
 // Initialize the timer
 void timer_init()
 {
-    // Enable MCYCLE counter
-    CSR_CLEAR_BITS(CSR_REG_MCOUNTINHIBIT, 0x1);
+    // Get current Frequency
+    soc_ctrl_t soc_ctrl;
+    soc_ctrl.base_addr = mmio_region_from_addr((uintptr_t)SOC_CTRL_START_ADDRESS);
+    uint32_t freq_hz = soc_ctrl_get_frequency(&soc_ctrl);
+
+    // Initialize the timer
+    rv_timer_init(timer_base, timer_cfg, &timer);
+    rv_timer_approximate_tick_params(freq_hz, freq_hz, &tick_params);
+    rv_timer_set_tick_params(&timer, 0, tick_params);
+    rv_timer_counter_set_enabled(&timer, 0, kRvTimerEnabled);
+}
+
+// Initialize the timer
+void timer_init_us()
+{
+    // Get current Frequency
+    soc_ctrl_t soc_ctrl;
+    soc_ctrl.base_addr = mmio_region_from_addr((uintptr_t)SOC_CTRL_START_ADDRESS);
+    uint32_t freq_hz = soc_ctrl_get_frequency(&soc_ctrl);
+
+    // Initialize the timer
+    rv_timer_init(timer_base, timer_cfg, &timer);
+    rv_timer_approximate_tick_params(freq_hz, FREQ_US, &tick_params);
+    rv_timer_set_tick_params(&timer, 0, tick_params);
+    rv_timer_counter_set_enabled(&timer, 0, kRvTimerEnabled);
+}
+
+// Initialize the timer
+void timer_wait_ms(uint32_t ms)
+{
+    timer_init_us();
+    timer_irq_enable();
+    timer_arm_start(ms*1000);
+    timer_start();              
+    asm volatile ("wfi");
+    timer_irq_clear();
+    return;
+}
+
+void enable_timer_interrupt()
+{
+    //enable timer interrupt
+    CSR_SET_BITS(CSR_REG_MSTATUS, 0x8);
+    // Set mie.MEIE bit to one to enable machine-level timer interrupts
+    const uint32_t mask = 1 << 7;
+    CSR_SET_BITS(CSR_REG_MIE, mask);
 }

sw/device/lib/sdk/timer/timer_sdk.h

@@ -3,8 +3,8 @@
 // SPDX-License-Identifier: Apache-2.0 WITH SHL-2.1
 //
 // File: timer_sdk.h
-// Authors: Michele Caon, Luigi Giuffrida
-// Date: 31/07/2023
+// Authors: Michele Caon, Luigi Giuffrida, Francesco Poluzzi
+// Date: 23/07/2024
 // Description: Execution time measurements utilities
 
 #ifndef TIMER_SDK_H_
@@ -20,6 +20,7 @@
 #include "x-heep.h"
 
 #define TICK_FREQ 1000000
+#define FREQ_US 1000000
 
 /******************************/
 /* ---- GLOBAL VARIABLES ---- */
@@ -35,12 +36,6 @@ extern rv_timer_t timer;
 /* ---- EXPORTED FUNCTIONS ---- */
 /********************************/
 
-/**
- * @brief Initialize the hardware timer
- * 
- */
-void hw_timer_init();
-
 /**
  * @brief Get the current value of the HW timer
  * 
@@ -63,11 +58,17 @@ uint32_t hw_timer_stop();
 
 
 /**
- * @brief Initialize the timer
+ * @brief Initialize the timer for counting clock cycles
  * 
  */
 void timer_init();
 
+/**
+ * @brief Initialize the timer for counting microseconds
+ * 
+ */
+void timer_init_us();
+
 /**
  * @brief Get the current value of the MCYCLE CSR
  * 
@@ -84,7 +85,7 @@ inline uint32_t timer_get_cycles() {
  * 
  */
 inline void timer_start() {
-    timer_value = -timer_get_cycles();
+    hw_timer_start();
 }
 
 /**
@@ -93,8 +94,39 @@ inline void timer_start() {
  * @return int64_t Elapsed time in clock cycles
  */
 inline uint32_t timer_stop() {
-    timer_value += timer_get_cycles();
-    return timer_value;
+    return hw_timer_stop();
 }
 
+/**
+ * @brief Enable the timer IRQ
+ */
+void timer_irq_enable();
+
+/**
+ * @brief Clear the timer IRQ
+ */
+void timer_irq_clear();
+
+/**
+ * @brief Arms the timer to go off once the counter value is greater than or equal to threshold
+ */
+void timer_arm_start(uint32_t threshold);
+
+/**
+ * @brief Stop to output when timer is greater than or equal to threshold previously set
+ */
+void timer_arm_stop();
+
+/**
+ * @brief Wait for a certain amount of milliseconds. Not precise with small
+ * numbers of milliseconds. 
+ * You need to enable timer interrupts with enable_timer_interrupt() before using this function
+ */
+void timer_wait_ms(uint32_t ms);
+
+/**
+ * @brief Enable the timer machine-level interrupts for X-Heep
+ */
+void enable_timer_interrupt();
+
 #endif /* TIMER_SDK_H_ */