versions/v1_4_0/mynewt-core/hw/mcu/ambiq/src/ext/AmbiqSuite/utils/am_util_delay.c

//*****************************************************************************
//
//! @file am_util_delay.c
//!
//! @brief A few useful delay functions.
//!
//! Functions for fixed delays.
//
//*****************************************************************************

//*****************************************************************************
//
// Copyright (c) 2017, Ambiq Micro
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
// 
// 1. Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// 
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// 
// 3. Neither the name of the copyright holder nor the names of its
// contributors may be used to endorse or promote products derived from this
// software without specific prior written permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// This is part of revision v1.2.10-2-gea660ad-hotfix2 of the AmbiqSuite Development Package.
//
//*****************************************************************************
#include <stdint.h>
#include <stdbool.h>
#include "hal/am_hal_clkgen.h"
#include "hal/am_hal_flash.h"
#include "am_util_delay.h"

//*****************************************************************************
//
//! @brief Delays for a desired amount of loops.
//!
//! @param ui32CycleLoops - Desired number of cycle loops to delay for.
//!
//! This function will delay for a number of cycle loops.
//!
//! @note - the number of cycles each loops takes to execute is approximately 3.
//! Therefore the actual number of cycles executed will be ~3x ui32CycleLoops.
//!
//! For example, a ui32CycleLoops value of 100 will delay for 300 cycles.
//!
//! @returns None
//
//*****************************************************************************
void
am_util_delay_cycles(uint32_t ui32Iterations)
{
    //
    // Call the BOOTROM cycle delay function
    //
    am_hal_flash_delay(ui32Iterations);
}

//*****************************************************************************
//
//! @brief Delays for a desired amount of milliseconds.
//!
//! @param ui32MilliSeconds - number of milliseconds to delay for.
//!
//! This function will delay for a number of milliseconds.
//!
//! @returns None
//
//*****************************************************************************
void
am_util_delay_ms(uint32_t ui32MilliSeconds)
{
    uint32_t ui32Loops = ui32MilliSeconds *
                          (am_hal_clkgen_sysclk_get() / 3000);

    //
    // Call the BOOTROM cycle delay function
    //
    am_hal_flash_delay(ui32Loops);
}

//*****************************************************************************
//
//! @brief Delays for a desired amount of microseconds.
//!
//! @param ui32MicroSeconds - number of microseconds to delay for.
//!
//! This function will delay for a number of microseconds.
//!
//! @returns None
//
//*****************************************************************************
void
am_util_delay_us(uint32_t ui32MicroSeconds)
{
    uint32_t ui32Loops = ui32MicroSeconds *
                          (am_hal_clkgen_sysclk_get() / 3000000);

    //
    // Call the BOOTROM cycle delay function
    //
    am_hal_flash_delay(ui32Loops);
}
//*****************************************************************************
//
//! @brief Delays for a desired amount of cycles while also waiting for a
//! status change.
//!
//! @param ui32CycleLoops - Desired number of cycle loops to delay for.
//! @param ui32Address - Address of the register for the status change.
//! @param ui32Mask - Mask for the status change.
//! @param ui32Value - Value for the status change.
//!
//! This function will delay for a number of cycle loops while checking for
//! a status change, exiting either when the number of cycles is exhausted
//! or the status change is detected.
//!
//! @note - the number of cycles each loops takes to execute is approximately 3.
//! Therefore the actual number of cycles executed will be ~3x ui32CycleLoops.
//!
//! For example, a ui32CycleLoops value of 100 will delay for 300 cycles.
//!
//! @returns 0 = timeout; 1 = status change detected.
//
//*****************************************************************************
uint32_t
am_util_wait_status_change(uint32_t ui32Iterations,
		uint32_t ui32Address, uint32_t ui32Mask, uint32_t ui32Value)
{
	for (uint32_t i = 0; i < ui32Iterations; i++)
	{
		// Check the status
		if (((*(volatile uint32_t *)ui32Address) & ui32Mask) == ui32Value)
		{
			return 1;
		}
        // Call the BOOTROM cycle delay function to get about 1 usec @ 48MHz
        am_hal_flash_delay(16);
	}
	return 0;
}