Added timer SDK and its respective example (#554)

sw/applications/example_timer_sdk/main.c

@@ -0,0 +1,56 @@
+// Copyright 2024 EPFL
+// Solderpad Hardware License, Version 2.1, see LICENSE.md for details.
+// SPDX-License-Identifier: Apache-2.0 WITH SHL-2.1
+//
+// File: example_timer_sdk.c
+// Author: Juan Sapriza
+// Date: 15/07/2024
+// Description: Example application to test the Timer SDK. Will count the time to execute a few short tasks.
+
+#include <stdint.h>
+#include <stdlib.h>
+#include "core_v_mini_mcu.h"
+#include "timer_sdk.h"
+#include "x-heep.h"
+
+/* By default, printfs are activated for FPGA and disabled for simulation. */
+#define PRINTF_IN_FPGA  1
+#define PRINTF_IN_SIM   0
+
+#if TARGET_SIM && PRINTF_IN_SIM
+        #define PRINTF(fmt, ...)    printf(fmt, ## __VA_ARGS__)
+#elif PRINTF_IN_FPGA && !TARGET_SIM
+    #define PRINTF(fmt, ...)    printf(fmt, ## __VA_ARGS__)
+#else
+    #define PRINTF(...)
+#endif
+
+int main(){
+    uint8_t i = 0;
+    uint32_t cpu_cycles;
+
+    timer_init();               // Init the timer SDK
+    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_start();              
+    asm volatile ("nop");
+    cpu_cycles = timer_stop();  
+    PRINTF("1 NOP:\t%d cc\n\r", cpu_cycles );
+
+    timer_start();              
+    asm volatile ("nop");
+    asm volatile ("nop");
+    cpu_cycles = timer_stop();  
+    PRINTF("2 NOPs:\t%d cc\n\r", cpu_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 );
+
+    return EXIT_SUCCESS;
+}

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

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+// Copyright 2023 EPFL and Politecnico di Torino.
+// Solderpad Hardware License, Version 2.1, see LICENSE.md for details.
+// SPDX-License-Identifier: Apache-2.0 WITH SHL-2.1
+//
+// File: timer_sdk.c
+// Author: Michele Caon
+// Date: 31/07/2023
+// Description: Timer functions
+
+#include <stdint.h>
+
+#include "timer_sdk.h"
+#include "csr.h"
+
+/******************************/
+/* ---- GLOBAL VARIABLES ---- */
+/******************************/
+
+// Timer value
+uint32_t timer_value = 0;
+uint32_t hw_timer_value = 0;
+
+rv_timer_t timer;
+
+rv_timer_config_t timer_cfg = {
+    .hart_count = RV_TIMER_PARAM_N_HARTS,
+    .comparator_count = RV_TIMER_PARAM_N_TIMERS,
+};
+
+mmio_region_t timer_base = {
+    .base = (void *)RV_TIMER_AO_START_ADDRESS,
+};
+
+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, true);
+}
+
+uint32_t hw_timer_get_cycles()
+{
+    uint64_t cycle_count;
+    rv_timer_counter_read(&timer, 0, &cycle_count);
+    return (uint32_t)cycle_count;
+}
+
+void hw_timer_start()
+{
+    hw_timer_value = -hw_timer_get_cycles();
+}
+
+uint32_t hw_timer_stop()
+{
+    hw_timer_value += hw_timer_get_cycles();
+    return hw_timer_value;
+}
+
+// Initialize the timer
+void timer_init()
+{
+    // Enable MCYCLE counter
+    CSR_CLEAR_BITS(CSR_REG_MCOUNTINHIBIT, 0x1);
+}

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

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+// Copyright 2023 EPFL and Politecnico di Torino.
+// Solderpad Hardware License, Version 2.1, see LICENSE.md for details.
+// SPDX-License-Identifier: Apache-2.0 WITH SHL-2.1
+//
+// File: timer_sdk.h
+// Authors: Michele Caon, Luigi Giuffrida
+// Date: 31/07/2023
+// Description: Execution time measurements utilities
+
+#ifndef TIMER_SDK_H_
+#define TIMER_SDK_H_
+
+#include <stdint.h>
+
+#include "csr.h"
+#include "gpio.h"
+#include "rv_timer.h"
+#include "rv_timer_regs.h"
+#include "core_v_mini_mcu.h"
+#include "x-heep.h"
+
+#define TICK_FREQ 1000000
+
+/******************************/
+/* ---- GLOBAL VARIABLES ---- */
+/******************************/
+
+// Timer value
+extern uint32_t timer_value;
+extern uint32_t hw_timer_value;
+
+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
+ * 
+* @return int64_t Current value of the HW timer
+ */
+uint32_t hw_timer_get_cycles();
+
+/**
+ * @brief Start the HW timer
+ * 
+ */
+void hw_timer_start();
+
+/**
+ * @brief Stop the HW timer
+ * 
+ * @return int64_t Elapsed time in clock cycles
+ */
+uint32_t hw_timer_stop();
+
+
+/**
+ * @brief Initialize the timer
+ * 
+ */
+void timer_init();
+
+/**
+ * @brief Get the current value of the MCYCLE CSR
+ * 
+ * @return int64_t Current value of the MCYCLE CSR
+ */
+inline uint32_t timer_get_cycles() {
+    uint32_t cycle_count;
+    CSR_READ(CSR_REG_MCYCLE, &cycle_count);
+    return cycle_count;
+}
+
+/**
+ * @brief Start the timer
+ * 
+ */
+inline void timer_start() {
+    timer_value = -timer_get_cycles();
+}
+
+/**
+ * @brief Stop the timer
+ * 
+ * @return int64_t Elapsed time in clock cycles
+ */
+inline uint32_t timer_stop() {
+    timer_value += timer_get_cycles();
+    return timer_value;
+}
+
+#endif /* TIMER_SDK_H_ */