141 lines
4.1 KiB
C
141 lines
4.1 KiB
C
/*
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* This file is part of the libopencm3 project.
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*
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* Copyright (C) 2010 Thomas Otto <tommi@viadmin.org>
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*
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* This library is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this library. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <libopencm3/stm32/f1/rcc.h>
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#include <libopencm3/stm32/f1/flash.h>
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#include <libopencm3/stm32/f1/gpio.h>
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#include <libopencm3/stm32/f1/dma.h>
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#include <libopencm3/stm32/usart.h>
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void usart_setup(void)
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{
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/* Enable clocks for GPIO port A (for GPIO_USART1_TX) and USART1. */
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rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPAEN);
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rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_USART1EN);
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/* Setup GPIO pin GPIO_USART1_TX/GPIO9 on GPIO port A for transmit. */
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gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ,
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GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART1_TX);
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/* Setup UART parameters. */
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usart_set_baudrate(USART1, 115200);
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usart_set_databits(USART1, 8);
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usart_set_stopbits(USART1, USART_STOPBITS_1);
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usart_set_mode(USART1, USART_MODE_TX_RX);
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usart_set_parity(USART1, USART_PARITY_NONE);
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usart_set_flow_control(USART1, USART_FLOWCONTROL_NONE);
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/* Finally enable the USART. */
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usart_enable(USART1);
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}
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void gpio_setup(void)
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{
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/* Enable GPIOB clock. */
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rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPBEN);
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/* Set GPIO6/7 (in GPIO port B) to 'output push-pull' for the LEDs. */
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gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_2_MHZ,
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GPIO_CNF_OUTPUT_PUSHPULL, GPIO6);
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gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_2_MHZ,
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GPIO_CNF_OUTPUT_PUSHPULL, GPIO7);
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}
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void my_usart_print_string(u32 usart, char *s)
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{
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while (*s != 0) {
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usart_send(usart, *s);
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s++;
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}
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}
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int main(void)
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{
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/*
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* Exactly 20 bytes including '\0' at the end.
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* We want to transfer 32bit * 5 so it should fit.
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*/
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char s1[20] = "Hello STM MEM2MEM\r\n";
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char s2[20];
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rcc_clock_setup_in_hse_16mhz_out_72mhz();
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gpio_setup();
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usart_setup();
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gpio_clear(GPIOB, GPIO7); /* LED1 on */
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gpio_set(GPIOB, GPIO6); /* LED2 off */
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my_usart_print_string(USART1, "s1 ");
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my_usart_print_string(USART1, s1);
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rcc_peripheral_enable_clock(&RCC_AHBENR, RCC_AHBENR_DMA1EN);
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/* MEM2MEM mode for channel 1. */
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dma_enable_mem2mem_mode(DMA1, DMA_CHANNEL1);
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/* Highest priority. */
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dma_set_priority(DMA1, DMA_CHANNEL1, DMA_CCR_PL_VERY_HIGH);
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/* 32Bit wide transfer for source and destination. */
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dma_set_memory_size(DMA1, DMA_CHANNEL1, DMA_CCR_MSIZE_32BIT);
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dma_set_peripheral_size(DMA1, DMA_CHANNEL1, DMA_CCR_PSIZE_32BIT);
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/*
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* After every 32bits we have to increase the address because
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* we use RAM.
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*/
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dma_enable_memory_increment_mode(DMA1, DMA_CHANNEL1);
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dma_enable_peripheral_increment_mode(DMA1, DMA_CHANNEL1);
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/* We define the source as peripheral. */
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dma_set_read_from_peripheral(DMA1, DMA_CHANNEL1);
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/* We want to transfer string s1. */
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dma_set_peripheral_address(DMA1, DMA_CHANNEL1, (u32)&s1);
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/* Destination should be string s2. */
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dma_set_memory_address(DMA1, DMA_CHANNEL1, (u32)&s2);
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/*
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* Set number of DATA to transfer.
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* Remember that this means not necessary bytes but MSIZE or PSIZE
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* depending on your source device.
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*/
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dma_set_number_of_data(DMA1, DMA_CHANNEL1, 5);
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/* Start DMA transfer. */
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dma_enable_channel(DMA1, DMA_CHANNEL1);
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/* TODO: Write a function to get the interrupt flags. */
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while (!(DMA_ISR(DMA1) & 0x0000001))
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;
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dma_disable_channel(DMA1, DMA_CHANNEL1);
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/* String s1 should now already be transferred to s2. */
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my_usart_print_string(USART1, "s2 ");
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my_usart_print_string(USART1, s2);
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gpio_clear(GPIOB, GPIO6); /* LED2 on */
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while (1); /* Halt. */
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return 0;
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}
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