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[example] Add delay measurement example
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@salkinium
salkinium committed Jun 15, 2021
1 parent 4fc0d01 commit 35ada08
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207 changes: 207 additions & 0 deletions examples/generic/delay/main.cpp
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/*
* Copyright (c) 2021, Niklas Hauser
*
* This file is part of the modm project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
// ----------------------------------------------------------------------------

#include <modm/board.hpp>

using namespace Board;

#ifdef CFG_TUSB_MCU
#include <modm/debug.hpp>
modm::IODeviceWrapper<UsbUart0, modm::IOBuffer::DiscardIfFull> usb_io_device;
modm::log::Logger modm::log::info(usb_io_device);
#endif

static void
run_delay_ns(uint32_t ns)
{
#ifdef CFG_TUSB_MCU
tud_task();
#endif
uint32_t start, stop;
{
modm::atomic::Lock _;
#ifdef DWT
start = DWT->CYCCNT;
#else
SysTick->CTRL = SysTick_CTRL_ENABLE_Msk | SysTick_CTRL_CLKSOURCE_Msk;
SysTick->LOAD = (1ul << 23);
SysTick->VAL = 0;
stop = SysTick->VAL;
#endif
modm::delay_ns(ns);
#ifdef DWT
stop = DWT->CYCCNT;
#else
start = SysTick->VAL;
#endif
}
#ifdef CFG_TUSB_MCU
tud_task();
#endif
const uint32_t cycles = (stop - start) - 4;
const uint32_t expected = uint64_t(SystemCoreClock) * ns / 1'000'000'000ull;
const uint32_t real = cycles * 1'000'000'000ull / SystemCoreClock;
MODM_LOG_INFO.printf("%8lu | %7lu | %7lu | %8lu %c\n", ns, expected, cycles, real,
(cycles < expected*1.2f ? (cycles > expected*0.8f ? ' ' : '<') : '>')) << modm::flush;
#ifdef CFG_TUSB_MCU
tud_task();
#endif
}

static void
run_delay_us(uint32_t us)
{
#ifdef CFG_TUSB_MCU
tud_task();
#endif
uint32_t start, stop;
{
modm::atomic::Lock _;
#ifdef DWT
start = DWT->CYCCNT;
#else
SysTick->CTRL = SysTick_CTRL_ENABLE_Msk | SysTick_CTRL_CLKSOURCE_Msk;
SysTick->LOAD = (1ul << 23);
SysTick->VAL = 0;
stop = SysTick->VAL;
#endif
modm::delay_us(us);
#ifdef DWT
stop = DWT->CYCCNT;
#else
start = SysTick->VAL;
#endif
}
#ifdef CFG_TUSB_MCU
tud_task();
#endif
const uint32_t cycles = (stop - start) - 4;
const uint32_t expected = uint64_t(SystemCoreClock) * us / 1'000'000ull;
const uint32_t real = cycles * 1'000'000ull / SystemCoreClock;
MODM_LOG_INFO.printf("%8lu | %8lu | %8lu | %8lu %c\n", us, expected, cycles, real,
(cycles < expected*1.2f ? (cycles > expected*0.8f ? ' ' : '<') : '>')) << modm::flush;
#ifdef CFG_TUSB_MCU
tud_task();
#endif
}

static void
run_test_ns(bool short_test=false)
{
MODM_LOG_INFO << "\nmodm::delay_ns for system clock = " << SystemCoreClock << modm::endl;
MODM_LOG_INFO << " expected | measured\n";
MODM_LOG_INFO << " ns | cycles | cycles | ns\n";

if (short_test)
{
run_delay_ns( 100);
run_delay_ns( 1'000);
run_delay_ns( 10'000);
run_delay_ns( 100'000);
run_delay_ns( 1'000'000);
run_delay_ns(10'000'000);
}
else
{
run_delay_ns(1);
run_delay_ns(5);
run_delay_ns(10);
for (uint32_t ii= 50; ii < 1000; ii += 50) run_delay_ns(ii);
for (uint32_t ii=1000; ii < 2000; ii += 100) run_delay_ns(ii);
for (uint32_t ii=2000; ii <= 10000; ii += 1000) run_delay_ns(ii);
run_delay_ns(100'000);
run_delay_ns(1'000'000);
run_delay_ns(10'000'000);
}
}

static void
run_test_us(bool short_test=false)
{
MODM_LOG_INFO << "\nmodm::delay_us for boot clock = " << SystemCoreClock << modm::endl;
MODM_LOG_INFO << " expected | measured\n";
MODM_LOG_INFO << " us | cycles | cycles | us\n";

if (short_test)
{
run_delay_us(1);
run_delay_us(5);
for (uint32_t ii=10; ii < 100; ii += 10) run_delay_us(ii);
run_delay_us(1'000);
}
else
{
run_delay_us( 1);
run_delay_us( 5);
run_delay_us( 10);
run_delay_us( 100);
run_delay_us( 1'000);
run_delay_us( 10'000);
run_delay_us(100'000);
}
}

#ifndef CFG_TUSB_MCU
// STM32 device
struct BootClock
{
// It may be necessary to scale these, due to clock prescalers != 1
static constexpr uint32_t Usart1 = Rcc::BootFrequency;
static constexpr uint32_t Usart2 = Rcc::BootFrequency;
static constexpr uint32_t Usart3 = Rcc::BootFrequency;
static constexpr uint32_t Usart4 = Rcc::BootFrequency;
static constexpr uint32_t Usart5 = Rcc::BootFrequency;
};
int main()
{
Board::stlink::Uart::connect<Board::stlink::Tx::Tx>();
Board::stlink::Uart::initialize<BootClock, 115200_Bd, 5_pct>();

run_test_ns(true);
run_test_us(true);

Board::initialize();

run_test_ns();
run_test_us();

while(true) {}
return 0;
}

#else
// SAMD21
int main()
{
Board::initialize();
Board::initializeUsbFs();
tusb_init();

MODM_LOG_INFO << "Hello World\n";

static int32_t counter{0};
while (true)
{
tud_task();

if (counter-- < 0)
{
Leds::toggle();
counter = 1'000'000;
MODM_LOG_INFO << modm::platform::delay_ns_per_loop << modm::endl;
run_test_ns();
run_test_us(true);
}
}
return 0;
}

#endif
24 changes: 24 additions & 0 deletions examples/generic/delay/project.xml
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<library>
<!-- <extends>modm:nucleo-l152re</extends> -->
<!-- <extends>modm:nucleo-f103rb</extends> -->
<!-- <extends>modm:nucleo-f401re</extends> -->
<!-- <extends>modm:nucleo-f411re</extends> -->
<!-- <extends>modm:nucleo-f446re</extends> -->
<extends>modm:nucleo-f334r8</extends>
<!-- <extends>modm:nucleo-f303k8</extends> -->
<!-- <extends>modm:nucleo-l476rg</extends> -->
<!-- <extends>modm:disco-f746ng</extends> -->
<!-- <extends>modm:nucleo-g071rb</extends> -->
<!-- <extends>modm:nucleo-f072rb</extends> -->
<!-- <extends>modm:nucleo-f091rc</extends> -->
<!-- <extends>modm:samd21-mini</extends> -->
<options>
<option name="modm:build:build.path">../../../build/generic/delay</option>
<!-- <option name="modm:tinyusb:config">device.cdc</option> -->
</options>
<modules>
<module>modm:build:scons</module>
<module>modm:debug</module>
<!-- <module>modm:tinyusb</module> -->
</modules>
</library>

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