added prescaler for 16 bit pwm in LPC1347 target
Fork of mbed-dev by
Diff: targets/hal/TARGET_Maxim/TARGET_MAX32600/us_ticker.c
- Revision:
- 144:ef7eb2e8f9f7
- Parent:
- 0:9b334a45a8ff
--- a/targets/hal/TARGET_Maxim/TARGET_MAX32600/us_ticker.c Tue Aug 02 14:07:36 2016 +0000 +++ b/targets/hal/TARGET_Maxim/TARGET_MAX32600/us_ticker.c Fri Sep 02 15:07:44 2016 +0100 @@ -1,263 +1,263 @@ -/******************************************************************************* - * Copyright (C) 2015 Maxim Integrated Products, Inc., All Rights Reserved. - * - * 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 MAXIM INTEGRATED 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. - * - * Except as contained in this notice, the name of Maxim Integrated - * Products, Inc. shall not be used except as stated in the Maxim Integrated - * Products, Inc. Branding Policy. - * - * The mere transfer of this software does not imply any licenses - * of trade secrets, proprietary technology, copyrights, patents, - * trademarks, maskwork rights, or any other form of intellectual - * property whatsoever. Maxim Integrated Products, Inc. retains all - * ownership rights. - ******************************************************************************* - */ - -#include "mbed_error.h" -#include "us_ticker_api.h" -#include "PeripheralNames.h" -#include "tmr_regs.h" - -#define US_TIMER MXC_TMR0 -#define US_TIMER_IRQn TMR0_IRQn - -static int us_ticker_inited = 0; -static uint32_t ticks_per_us; -static uint32_t tick_win; -static volatile uint64_t current_cnt; // Hold the current ticks -static volatile uint64_t event_cnt; // Holds the value of the next event - -#define ticks_to_us(ticks) ((ticks) / ticks_per_us); -#define MAX_TICK_VAL ((uint64_t)0xFFFFFFFF * ticks_per_us) - -//****************************************************************************** -static inline void inc_current_cnt(uint32_t inc) { - - // Overflow the ticker when the us ticker overflows - current_cnt += inc; - if (current_cnt > MAX_TICK_VAL) { - current_cnt -= (MAX_TICK_VAL + 1); - } -} - -//****************************************************************************** -static inline int event_passed(uint64_t current, uint64_t event) { - - // Determine if the event has already happened. - // If the event is behind the current ticker, within a window, - // then the event has already happened. - if (((current < tick_win) && ((event < current) || - (event > (MAX_TICK_VAL - (tick_win - current))))) || - ((event < current) && (event > (current - tick_win)))) { - return 1; - } - - return 0; -} - -//****************************************************************************** -static inline uint64_t event_diff(uint64_t current, uint64_t event) { - - // Check to see if the ticker will overflow before the event - if(current <= event) { - return (event - current); - } - - return ((MAX_TICK_VAL - current) + event); -} - -//****************************************************************************** -static void tmr_handler(void) -{ - uint32_t term_cnt32 = US_TIMER->term_cnt32; - US_TIMER->term_cnt32 = 0xFFFFFFFF; // reset to max value to prevent further interrupts - US_TIMER->intfl = (MXC_F_TMR_INTFL_TIMER0 | MXC_F_TMR_INTFL_TIMER1); // clear interrupt - NVIC_ClearPendingIRQ(US_TIMER_IRQn); - - inc_current_cnt(term_cnt32); - - if (event_passed(current_cnt + US_TIMER->count32, event_cnt )) { - // the timestamp has expired - event_cnt = 0xFFFFFFFFFFFFFFFFULL; // reset to max value - us_ticker_irq_handler(); - } else { - - uint64_t diff = event_diff(current_cnt, event_cnt); - if (diff < (uint64_t)0xFFFFFFFF) { - // the event occurs before the next overflow - US_TIMER->term_cnt32 = diff; - - // Since the timer keeps counting after the terminal value is reached, it is possible that the new - // terminal value is in the past. - if (US_TIMER->term_cnt32 < US_TIMER->count32) { - // the timestamp has expired - US_TIMER->term_cnt32 = 0xFFFFFFFF; // reset to max value to prevent further interrupts - US_TIMER->intfl = (MXC_F_TMR_INTFL_TIMER0 | MXC_F_TMR_INTFL_TIMER1); // clear interrupt - NVIC_ClearPendingIRQ(US_TIMER_IRQn); - event_cnt = 0xFFFFFFFFFFFFFFFFULL; // reset to max value - us_ticker_irq_handler(); - } - } - } -} - -//****************************************************************************** -void us_ticker_init(void) -{ - if (us_ticker_inited) - return; - us_ticker_inited = 1; - - current_cnt = 0; - event_cnt = 0xFFFFFFFFFFFFFFFFULL; // reset to max value - - if (SystemCoreClock <= 1000000) { - error("us_ticker cannot operate at this SystemCoreClock"); - return; - } - - // Configure timer for 32-bit continuous mode with /1 prescaler - US_TIMER->ctrl = MXC_E_TMR_MODE_CONTINUOUS << MXC_F_TMR_CTRL_MODE_POS | (0 << MXC_F_TMR_CTRL_PRESCALE_POS); - ticks_per_us = SystemCoreClock / 1000000; - - // Set the tick window to 10ms - tick_win = SystemCoreClock/100; - - // Set timer overflow to the max - US_TIMER->term_cnt32 = 0xFFFFFFFF; - US_TIMER->pwm_cap32 = 0xFFFFFFFF; - US_TIMER->count32 = 0; - - US_TIMER->intfl = (MXC_F_TMR_INTFL_TIMER0 | MXC_F_TMR_INTFL_TIMER1); // clear pending interrupts - - NVIC_SetVector(US_TIMER_IRQn, (uint32_t)tmr_handler); - NVIC_EnableIRQ(US_TIMER_IRQn); - - US_TIMER->inten |= MXC_F_TMR_INTEN_TIMER0; // enable interrupts - US_TIMER->ctrl |= MXC_F_TMR_CTRL_ENABLE0; // enable timer -} - -//****************************************************************************** -void us_ticker_deinit(void) -{ - US_TIMER->ctrl = 0; // disable timer - US_TIMER->inten = 0; // disable interrupts - US_TIMER->intfl = (MXC_F_TMR_INTFL_TIMER0 | MXC_F_TMR_INTFL_TIMER1); // clear interrupts - us_ticker_inited = 0; -} - -//****************************************************************************** -uint32_t us_ticker_read(void) -{ - uint64_t current_cnt1, current_cnt2; - uint32_t term_cnt, tmr_cnt; - uint32_t intfl1, intfl2; - - if (!us_ticker_inited) - us_ticker_init(); - - // Ensure coherency between current_cnt and US_TIMER->count32 - do { - current_cnt1 = current_cnt; - intfl1 = US_TIMER->intfl; - term_cnt = US_TIMER->term_cnt32; - tmr_cnt = US_TIMER->count32; - intfl2 = US_TIMER->intfl; - current_cnt2 = current_cnt; - } while ((current_cnt1 != current_cnt2) || (intfl1 != intfl2)); - - // Account for an unserviced interrupt - if (intfl1) { - current_cnt1 += term_cnt; - } - - current_cnt1 += tmr_cnt; - - return (current_cnt1 / ticks_per_us); -} - -//****************************************************************************** -void us_ticker_set_interrupt(timestamp_t timestamp) -{ - // Note: interrupts are disabled before this function is called. - - US_TIMER->ctrl &= ~MXC_F_TMR_CTRL_ENABLE0; // disable timer - - if (US_TIMER->intfl) { - US_TIMER->intfl = (MXC_F_TMR_INTFL_TIMER0 | MXC_F_TMR_INTFL_TIMER1); // clear interrupt - NVIC_ClearPendingIRQ(US_TIMER_IRQn); - inc_current_cnt(US_TIMER->term_cnt32); - } - - // add and reset the current count value - inc_current_cnt(US_TIMER->count32); - US_TIMER->count32 = 0; - - // add the number of cycles that the timer is disabled here for - inc_current_cnt(200); - - event_cnt = (uint64_t)timestamp * ticks_per_us; - - // Check to see if the event has already passed - if (!event_passed(current_cnt, event_cnt)) { - uint64_t diff = event_diff(current_cnt, event_cnt); - if (diff < (uint64_t)0xFFFFFFFF) { - // the event occurs before the next overflow - US_TIMER->term_cnt32 = diff; - } else { - // the event occurs after the next overflow - US_TIMER->term_cnt32 = 0xFFFFFFFF; // set to max - } - } else { - // the requested timestamp occurs in the past - // set the timer up to immediately expire - US_TIMER->term_cnt32 = 1; - } - US_TIMER->ctrl |= MXC_F_TMR_CTRL_ENABLE0; // enable timer -} - -//****************************************************************************** -void us_ticker_disable_interrupt(void) -{ - // There are no more events, set timer overflow to the max - US_TIMER->term_cnt32 = 0xFFFFFFFF; -} - -//****************************************************************************** -void us_ticker_clear_interrupt(void) -{ - // cleared in the local handler -} - -//****************************************************************************** -void us_ticker_set(timestamp_t timestamp) -{ - US_TIMER->ctrl &= ~MXC_F_TMR_CTRL_ENABLE0; // disable timer - current_cnt = (uint64_t)timestamp * ticks_per_us; - US_TIMER->count32 = 0; - US_TIMER->term_cnt32 = 0xFFFFFFFF; - US_TIMER->ctrl |= MXC_F_TMR_CTRL_ENABLE0; // enable timer - - if (((uint64_t)timestamp * ticks_per_us) >= event_cnt) { - // The next timestamp has elapsed. Trigger the interrupt to handle it. - NVIC_SetPendingIRQ(US_TIMER_IRQn); - } -} +/******************************************************************************* + * Copyright (C) 2015 Maxim Integrated Products, Inc., All Rights Reserved. + * + * 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 MAXIM INTEGRATED 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. + * + * Except as contained in this notice, the name of Maxim Integrated + * Products, Inc. shall not be used except as stated in the Maxim Integrated + * Products, Inc. Branding Policy. + * + * The mere transfer of this software does not imply any licenses + * of trade secrets, proprietary technology, copyrights, patents, + * trademarks, maskwork rights, or any other form of intellectual + * property whatsoever. Maxim Integrated Products, Inc. retains all + * ownership rights. + ******************************************************************************* + */ + +#include "mbed_error.h" +#include "us_ticker_api.h" +#include "PeripheralNames.h" +#include "tmr_regs.h" + +#define US_TIMER MXC_TMR0 +#define US_TIMER_IRQn TMR0_IRQn + +static int us_ticker_inited = 0; +static uint32_t ticks_per_us; +static uint32_t tick_win; +static volatile uint64_t current_cnt; // Hold the current ticks +static volatile uint64_t event_cnt; // Holds the value of the next event + +#define ticks_to_us(ticks) ((ticks) / ticks_per_us); +#define MAX_TICK_VAL ((uint64_t)0xFFFFFFFF * ticks_per_us) + +//****************************************************************************** +static inline void inc_current_cnt(uint32_t inc) { + + // Overflow the ticker when the us ticker overflows + current_cnt += inc; + if (current_cnt > MAX_TICK_VAL) { + current_cnt -= (MAX_TICK_VAL + 1); + } +} + +//****************************************************************************** +static inline int event_passed(uint64_t current, uint64_t event) { + + // Determine if the event has already happened. + // If the event is behind the current ticker, within a window, + // then the event has already happened. + if (((current < tick_win) && ((event < current) || + (event > (MAX_TICK_VAL - (tick_win - current))))) || + ((event < current) && (event > (current - tick_win)))) { + return 1; + } + + return 0; +} + +//****************************************************************************** +static inline uint64_t event_diff(uint64_t current, uint64_t event) { + + // Check to see if the ticker will overflow before the event + if(current <= event) { + return (event - current); + } + + return ((MAX_TICK_VAL - current) + event); +} + +//****************************************************************************** +static void tmr_handler(void) +{ + uint32_t term_cnt32 = US_TIMER->term_cnt32; + US_TIMER->term_cnt32 = 0xFFFFFFFF; // reset to max value to prevent further interrupts + US_TIMER->intfl = (MXC_F_TMR_INTFL_TIMER0 | MXC_F_TMR_INTFL_TIMER1); // clear interrupt + NVIC_ClearPendingIRQ(US_TIMER_IRQn); + + inc_current_cnt(term_cnt32); + + if (event_passed(current_cnt + US_TIMER->count32, event_cnt )) { + // the timestamp has expired + event_cnt = 0xFFFFFFFFFFFFFFFFULL; // reset to max value + us_ticker_irq_handler(); + } else { + + uint64_t diff = event_diff(current_cnt, event_cnt); + if (diff < (uint64_t)0xFFFFFFFF) { + // the event occurs before the next overflow + US_TIMER->term_cnt32 = diff; + + // Since the timer keeps counting after the terminal value is reached, it is possible that the new + // terminal value is in the past. + if (US_TIMER->term_cnt32 < US_TIMER->count32) { + // the timestamp has expired + US_TIMER->term_cnt32 = 0xFFFFFFFF; // reset to max value to prevent further interrupts + US_TIMER->intfl = (MXC_F_TMR_INTFL_TIMER0 | MXC_F_TMR_INTFL_TIMER1); // clear interrupt + NVIC_ClearPendingIRQ(US_TIMER_IRQn); + event_cnt = 0xFFFFFFFFFFFFFFFFULL; // reset to max value + us_ticker_irq_handler(); + } + } + } +} + +//****************************************************************************** +void us_ticker_init(void) +{ + if (us_ticker_inited) + return; + us_ticker_inited = 1; + + current_cnt = 0; + event_cnt = 0xFFFFFFFFFFFFFFFFULL; // reset to max value + + if (SystemCoreClock <= 1000000) { + error("us_ticker cannot operate at this SystemCoreClock"); + return; + } + + // Configure timer for 32-bit continuous mode with /1 prescaler + US_TIMER->ctrl = MXC_E_TMR_MODE_CONTINUOUS << MXC_F_TMR_CTRL_MODE_POS | (0 << MXC_F_TMR_CTRL_PRESCALE_POS); + ticks_per_us = SystemCoreClock / 1000000; + + // Set the tick window to 10ms + tick_win = SystemCoreClock/100; + + // Set timer overflow to the max + US_TIMER->term_cnt32 = 0xFFFFFFFF; + US_TIMER->pwm_cap32 = 0xFFFFFFFF; + US_TIMER->count32 = 0; + + US_TIMER->intfl = (MXC_F_TMR_INTFL_TIMER0 | MXC_F_TMR_INTFL_TIMER1); // clear pending interrupts + + NVIC_SetVector(US_TIMER_IRQn, (uint32_t)tmr_handler); + NVIC_EnableIRQ(US_TIMER_IRQn); + + US_TIMER->inten |= MXC_F_TMR_INTEN_TIMER0; // enable interrupts + US_TIMER->ctrl |= MXC_F_TMR_CTRL_ENABLE0; // enable timer +} + +//****************************************************************************** +void us_ticker_deinit(void) +{ + US_TIMER->ctrl = 0; // disable timer + US_TIMER->inten = 0; // disable interrupts + US_TIMER->intfl = (MXC_F_TMR_INTFL_TIMER0 | MXC_F_TMR_INTFL_TIMER1); // clear interrupts + us_ticker_inited = 0; +} + +//****************************************************************************** +uint32_t us_ticker_read(void) +{ + uint64_t current_cnt1, current_cnt2; + uint32_t term_cnt, tmr_cnt; + uint32_t intfl1, intfl2; + + if (!us_ticker_inited) + us_ticker_init(); + + // Ensure coherency between current_cnt and US_TIMER->count32 + do { + current_cnt1 = current_cnt; + intfl1 = US_TIMER->intfl; + term_cnt = US_TIMER->term_cnt32; + tmr_cnt = US_TIMER->count32; + intfl2 = US_TIMER->intfl; + current_cnt2 = current_cnt; + } while ((current_cnt1 != current_cnt2) || (intfl1 != intfl2)); + + // Account for an unserviced interrupt + if (intfl1) { + current_cnt1 += term_cnt; + } + + current_cnt1 += tmr_cnt; + + return (current_cnt1 / ticks_per_us); +} + +//****************************************************************************** +void us_ticker_set_interrupt(timestamp_t timestamp) +{ + // Note: interrupts are disabled before this function is called. + + US_TIMER->ctrl &= ~MXC_F_TMR_CTRL_ENABLE0; // disable timer + + if (US_TIMER->intfl) { + US_TIMER->intfl = (MXC_F_TMR_INTFL_TIMER0 | MXC_F_TMR_INTFL_TIMER1); // clear interrupt + NVIC_ClearPendingIRQ(US_TIMER_IRQn); + inc_current_cnt(US_TIMER->term_cnt32); + } + + // add and reset the current count value + inc_current_cnt(US_TIMER->count32); + US_TIMER->count32 = 0; + + // add the number of cycles that the timer is disabled here for + inc_current_cnt(200); + + event_cnt = (uint64_t)timestamp * ticks_per_us; + + // Check to see if the event has already passed + if (!event_passed(current_cnt, event_cnt)) { + uint64_t diff = event_diff(current_cnt, event_cnt); + if (diff < (uint64_t)0xFFFFFFFF) { + // the event occurs before the next overflow + US_TIMER->term_cnt32 = diff; + } else { + // the event occurs after the next overflow + US_TIMER->term_cnt32 = 0xFFFFFFFF; // set to max + } + } else { + // the requested timestamp occurs in the past + // set the timer up to immediately expire + US_TIMER->term_cnt32 = 1; + } + US_TIMER->ctrl |= MXC_F_TMR_CTRL_ENABLE0; // enable timer +} + +//****************************************************************************** +void us_ticker_disable_interrupt(void) +{ + // There are no more events, set timer overflow to the max + US_TIMER->term_cnt32 = 0xFFFFFFFF; +} + +//****************************************************************************** +void us_ticker_clear_interrupt(void) +{ + // cleared in the local handler +} + +//****************************************************************************** +void us_ticker_set(timestamp_t timestamp) +{ + US_TIMER->ctrl &= ~MXC_F_TMR_CTRL_ENABLE0; // disable timer + current_cnt = (uint64_t)timestamp * ticks_per_us; + US_TIMER->count32 = 0; + US_TIMER->term_cnt32 = 0xFFFFFFFF; + US_TIMER->ctrl |= MXC_F_TMR_CTRL_ENABLE0; // enable timer + + if (((uint64_t)timestamp * ticks_per_us) >= event_cnt) { + // The next timestamp has elapsed. Trigger the interrupt to handle it. + NVIC_SetPendingIRQ(US_TIMER_IRQn); + } +}