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https://github.com/licsber/micropython.git
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1c32cec7f1
The range is 1MHz - 48 MHz. Note that below 8 MHz there is no USB support. The frequency will be set to an integer fraction of 48 MHz. And after changing the frequency, the peripherals like PWM, UART, I2C, SPI have to be reconfigured. Current consumption e.g. of the Seeed Xiao board at 1 MHz is about 1.5 mA, mostly caused by the on-board LED (green LED with 1k resistor at 3.3V).
119 lines
4.1 KiB
C
119 lines
4.1 KiB
C
/*
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* This file is part of the MicroPython project, http://micropython.org/
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*
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* This file initialises the USB (tinyUSB) and USART (SERCOM). Board USART settings
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* are set in 'boards/<board>/mpconfigboard.h.
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*
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* IMPORTANT: Please refer to "I/O Multiplexing and Considerations" chapters
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* in device datasheets for I/O Pin functions and assignments.
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2019 Damien P. George
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* Copyright (c) 2022 Robert Hammelrath
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "py/runtime.h"
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#include "modmachine.h"
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#include "samd_soc.h"
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#include "sam.h"
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#include "tusb.h"
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#include "mphalport.h"
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static void usb_init(void) {
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// Init USB clock
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#if defined(MCU_SAMD21)
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GCLK->CLKCTRL.reg = GCLK_CLKCTRL_CLKEN | GCLK_CLKCTRL_GEN_GCLK5 | GCLK_CLKCTRL_ID_USB;
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PM->AHBMASK.bit.USB_ = 1;
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PM->APBBMASK.bit.USB_ = 1;
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uint8_t alt = 6; // alt G, USB
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#elif defined(MCU_SAMD51)
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GCLK->PCHCTRL[USB_GCLK_ID].reg = GCLK_PCHCTRL_CHEN | GCLK_PCHCTRL_GEN_GCLK5;
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while (GCLK->PCHCTRL[USB_GCLK_ID].bit.CHEN == 0) {
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}
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MCLK->AHBMASK.bit.USB_ = 1;
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MCLK->APBBMASK.bit.USB_ = 1;
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uint8_t alt = 7; // alt H, USB
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#endif
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// Init USB pins
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PORT->Group[0].DIRSET.reg = 1 << 25 | 1 << 24;
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PORT->Group[0].OUTCLR.reg = 1 << 25 | 1 << 24;
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PORT->Group[0].PMUX[12].reg = alt << 4 | alt;
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PORT->Group[0].PINCFG[24].reg = PORT_PINCFG_PMUXEN;
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PORT->Group[0].PINCFG[25].reg = PORT_PINCFG_PMUXEN;
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tusb_init();
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}
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// Initialize the microsecond counter on TC 0/1
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void init_us_counter(void) {
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#if defined(MCU_SAMD21)
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PM->APBCMASK.bit.TC3_ = 1; // Enable TC3 clock
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PM->APBCMASK.bit.TC4_ = 1; // Enable TC4 clock
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// Select multiplexer generic clock source and enable.
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GCLK->CLKCTRL.reg = GCLK_CLKCTRL_CLKEN | GCLK_CLKCTRL_GEN_GCLK3 | GCLK_CLKCTRL_ID_TC4_TC5;
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// Wait while it updates synchronously.
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while (GCLK->STATUS.bit.SYNCBUSY) {
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}
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// configure the timer
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TC4->COUNT32.CTRLA.bit.MODE = TC_CTRLA_MODE_COUNT32_Val;
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TC4->COUNT32.CTRLA.bit.RUNSTDBY = 1;
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TC4->COUNT32.CTRLA.bit.ENABLE = 1;
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while (TC4->COUNT32.STATUS.bit.SYNCBUSY) {
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}
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TC4->COUNT32.READREQ.reg = TC_READREQ_RREQ | TC_READREQ_RCONT | 0x10;
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while (TC4->COUNT32.STATUS.bit.SYNCBUSY) {
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}
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#elif defined(MCU_SAMD51)
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MCLK->APBAMASK.bit.TC0_ = 1; // Enable TC0 clock
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MCLK->APBAMASK.bit.TC1_ = 1; // Enable TC1 clock
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// Peripheral channel 9 is driven by GCLK3, 8 MHz.
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GCLK->PCHCTRL[TC0_GCLK_ID].reg = GCLK_PCHCTRL_GEN_GCLK3 | GCLK_PCHCTRL_CHEN;
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while (GCLK->PCHCTRL[TC0_GCLK_ID].bit.CHEN == 0) {
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}
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// configure the timer
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TC0->COUNT32.CTRLA.bit.PRESCALER = 0;
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TC0->COUNT32.CTRLA.bit.MODE = TC_CTRLA_MODE_COUNT32_Val;
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TC0->COUNT32.CTRLA.bit.RUNSTDBY = 1;
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TC0->COUNT32.CTRLA.bit.ENABLE = 1;
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while (TC0->COUNT32.SYNCBUSY.bit.ENABLE) {
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}
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#endif
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}
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void samd_init(void) {
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init_clocks(get_cpu_freq());
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SysTick_Config(get_cpu_freq() / 1000);
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init_us_counter();
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usb_init();
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check_usb_recovery_mode();
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#if defined(MCU_SAMD51)
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mp_hal_ticks_cpu_enable();
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#endif
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}
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