diff options
Diffstat (limited to 'libmaple/include/libmaple/systick.h')
-rw-r--r-- | libmaple/include/libmaple/systick.h | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/libmaple/include/libmaple/systick.h b/libmaple/include/libmaple/systick.h new file mode 100644 index 0000000..551f800 --- /dev/null +++ b/libmaple/include/libmaple/systick.h @@ -0,0 +1,115 @@ +/****************************************************************************** + * The MIT License + * + * Copyright (c) 2010 Perry Hung. + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + *****************************************************************************/ + +/** + * @file libmaple/include/libmaple/systick.h + * @brief System timer definitions + */ + +#ifndef _LIBMAPLE_SYSTICK_H_ +#define _LIBMAPLE_SYSTICK_H_ + +#ifdef __cplusplus +extern "C"{ +#endif + +#include <libmaple/libmaple_types.h> +#include <libmaple/util.h> + +/** SysTick register map type */ +typedef struct systick_reg_map { + __io uint32 CSR; /**< Control and status register */ + __io uint32 RVR; /**< Reload value register */ + __io uint32 CNT; /**< Current value register ("count") */ + __io uint32 CVR; /**< Calibration value register */ +} systick_reg_map; + +/** SysTick register map base pointer */ +#define SYSTICK_BASE ((struct systick_reg_map*)0xE000E010) + +/* + * Register bit definitions. + */ + +/* Control and status register */ + +#define SYSTICK_CSR_COUNTFLAG BIT(16) +#define SYSTICK_CSR_CLKSOURCE BIT(2) +#define SYSTICK_CSR_CLKSOURCE_EXTERNAL 0 +#define SYSTICK_CSR_CLKSOURCE_CORE BIT(2) +#define SYSTICK_CSR_TICKINT BIT(1) +#define SYSTICK_CSR_TICKINT_PEND BIT(1) +#define SYSTICK_CSR_TICKINT_NO_PEND 0 +#define SYSTICK_CSR_ENABLE BIT(0) +#define SYSTICK_CSR_ENABLE_MULTISHOT BIT(0) +#define SYSTICK_CSR_ENABLE_DISABLED 0 + +/* Calibration value register */ + +#define SYSTICK_CVR_NOREF BIT(31) +#define SYSTICK_CVR_SKEW BIT(30) +#define SYSTICK_CVR_TENMS 0xFFFFFF + +/** System elapsed time, in milliseconds */ +extern volatile uint32 systick_uptime_millis; + +/** + * @brief Returns the system uptime, in milliseconds. + */ +static inline uint32 systick_uptime(void) { + return systick_uptime_millis; +} + + +void systick_init(uint32 reload_val); +void systick_disable(); +void systick_enable(); + +/** + * @brief Returns the current value of the SysTick counter. + */ +static inline uint32 systick_get_count(void) { + return SYSTICK_BASE->CNT; +} + +/** + * @brief Check for underflow. + * + * This function returns 1 if the SysTick timer has counted to 0 since + * the last time it was called. However, any reads of any part of the + * SysTick Control and Status Register SYSTICK_BASE->CSR will + * interfere with this functionality. See the ARM Cortex M3 Technical + * Reference Manual for more details (e.g. Table 8-3 in revision r1p1). + */ +static inline uint32 systick_check_underflow(void) { + return SYSTICK_BASE->CSR & SYSTICK_CSR_COUNTFLAG; +} + +#ifdef __cplusplus +} // extern "C" +#endif + +#endif |