rtc, keeping time

1 files changed, 268 insertions, 0 deletions

diff --git a/drivers_nrf/delay/nrf_delay.h b/drivers_nrf/delay/nrf_delay.h
new file mode 100644
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+++ b/drivers_nrf/delay/nrf_delay.h
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+/**
+ * Copyright (c) 2011 - 2017, Nordic Semiconductor ASA
+ * 
+ * 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, except as embedded into a Nordic
+ *    Semiconductor ASA integrated circuit in a product or a software update for
+ *    such product, 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 Nordic Semiconductor ASA nor the names of its
+ *    contributors may be used to endorse or promote products derived from this
+ *    software without specific prior written permission.
+ * 
+ * 4. This software, with or without modification, must only be used with a
+ *    Nordic Semiconductor ASA integrated circuit.
+ * 
+ * 5. Any software provided in binary form under this license must not be reverse
+ *    engineered, decompiled, modified and/or disassembled.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA 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.
+ * 
+ */
+
+#ifndef _NRF_DELAY_H
+#define _NRF_DELAY_H
+
+#include "nrf.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define CLOCK_FREQ_16MHz (16000000UL)
+
+#ifdef NRF52_SERIES
+  #define CPU_FREQ_64MHz
+#endif
+
+/**
+ * @brief Function for delaying execution for number of microseconds.
+ *
+ * @note NRF52 has instruction cache and because of that delay is not precise.
+ *
+ * @param number_of_us
+ *
+ */
+/*lint --e{438, 522, 40, 10, 563} "Variable not used" "Function lacks side-effects" */
+__STATIC_INLINE void nrf_delay_us(uint32_t number_of_us);
+
+
+/**
+ * @brief Function for delaying execution for number of miliseconds.
+ *
+ * @note NRF52 has instruction cache and because of that delay is not precise.
+ *
+ * @note Function internally calls @ref nrf_delay_us so the maximum delay is the
+ * same as in case of @ref nrf_delay_us, approx. 71 minutes.
+ *
+ * @param number_of_ms
+ *
+ */
+
+/*lint --e{438, 522, 40, 10, 563} "Variable not used" "Function lacks side-effects" */
+__STATIC_INLINE void nrf_delay_ms(uint32_t number_of_ms);
+
+#if defined ( __CC_ARM   )
+__STATIC_INLINE void nrf_delay_us(uint32_t number_of_us)
+{
+    if(!number_of_us)
+        return;
+__asm
+    {
+loop:
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    CMP SystemCoreClock, CLOCK_FREQ_16MHz
+    BEQ cond
+    NOP
+#ifdef  CPU_FREQ_64MHz
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+    NOP
+#endif //CPU_FREQ_64MHz
+cond:
+    SUBS number_of_us,number_of_us, #1
+    BNE    loop
+    }
+}
+
+#elif defined ( _WIN32 ) || defined ( __unix ) || defined( __APPLE__ )
+
+
+#ifndef CUSTOM_NRF_DELAY_US
+__STATIC_INLINE void nrf_delay_us(uint32_t number_of_us)
+{}
+#endif
+
+#elif defined ( __GNUC__ ) || ( __ICCARM__ )
+
+__STATIC_INLINE void nrf_delay_us(uint32_t number_of_us)
+{
+    const uint32_t clock16MHz = CLOCK_FREQ_16MHz;
+    if (number_of_us)
+    {
+__ASM volatile (
+#if ( defined(__GNUC__) && (__CORTEX_M == (0x00U) ) )
+        ".syntax unified\n"
+#endif
+"1:\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " CMP %[SystemCoreClock],%[clock16MHz]\n"
+       " BEQ.n 2f\n"
+       " NOP\n"
+#ifdef  CPU_FREQ_64MHz
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+       " NOP\n"
+#endif //CPU_FREQ_64MHz
+"2:\n"
+       " SUBS %0, %0, #1\n"
+       " BNE.n 1b\n"
+#if __CORTEX_M == (0x00U)
+#ifdef __GNUC__
+    ".syntax divided\n"
+#endif
+    :"+l" (number_of_us) :
+#else
+    :"+r" (number_of_us) :
+#endif
+                [SystemCoreClock] "r" (SystemCoreClock),
+                [clock16MHz] "r" (clock16MHz)
+        );
+#ifdef __ICCARM__
+        __DMB();
+#endif
+    }
+}
+#endif
+
+__STATIC_INLINE void nrf_delay_ms(uint32_t number_of_ms)
+{
+    nrf_delay_us(1000*number_of_ms);
+}
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif