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[/] [neorv32/] [trunk/] [sw/] [lib/] [source/] [neorv32_pwm.c] - Rev 42
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// ################################################################################################# // # << NEORV32: neorv32_pwm.c - Pulse Width Modulation Controller (PWM) HW Driver >> # // # ********************************************************************************************* # // # BSD 3-Clause License # // # # // # Copyright (c) 2020, Stephan Nolting. 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. # // # ********************************************************************************************* # // # The NEORV32 Processor - https://github.com/stnolting/neorv32 (c) Stephan Nolting # // ################################################################################################# /**********************************************************************//** * @file neorv32_pwm.c * @author Stephan Nolting * @brief Pulse-Width Modulation Controller (PWM) HW driver source file. * * @note These functions should only be used if the PWM unit was synthesized (IO_PWM_USE = true). **************************************************************************/ #include "neorv32.h" #include "neorv32_pwm.h" /**********************************************************************//** * Check if PWM unit was synthesized. * * @return 0 if PWM was not synthesized, 1 if PWM is available. **************************************************************************/ int neorv32_pwm_available(void) { if (SYSINFO_FEATURES & (1 << SYSINFO_FEATURES_IO_PWM)) { return 1; } else { return 0; } } /**********************************************************************//** * Enable and configure pulse width modulation controller. The PWM control register bits are listed in #NEORV32_PWM_CT_enum. * * @param[in] prsc Clock prescaler select (0..7). See #NEORV32_CLOCK_PRSC_enum. **************************************************************************/ void neorv32_pwm_setup(uint8_t prsc) { PWM_CT = 0; // reset uint32_t ct_enable = 1; ct_enable = ct_enable << PWM_CT_EN; uint32_t ct_prsc = (uint32_t)(prsc & 0x07); ct_prsc = ct_prsc << PWM_CT_PRSC0; PWM_CT = ct_enable | ct_prsc; } /**********************************************************************//** * Disable pulse width modulation controller. **************************************************************************/ void neorv32_pwm_disable(void) { PWM_CT &= ~((uint32_t)(1 << PWM_CT_EN)); } /**********************************************************************//** * Set duty cycle for channel. The PWM duty cycle bits are listed in #NEORV32_PWM_DUTY_enum. * * @param[in] channel Channel select (0..3). * @param[in] duty Duty cycle (0..255). **************************************************************************/ void neorv32_pwm_set(uint8_t channel, uint8_t duty) { channel = channel & 0x03; uint32_t duty_mask = 0xff; uint32_t duty_new = (uint32_t)duty; duty_mask = duty_mask << (channel * 8); duty_new = duty_new << (channel * 8); uint32_t duty_cycle = PWM_DUTY; duty_cycle &= ~duty_mask; // clear previous duty cycle duty_cycle |= duty_new; // set new duty cycle PWM_DUTY = duty_cycle; }
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