Files
libopencm3-examples/examples/lm4f/stellaris-ek-lm4f120xl/uart_echo_simple/uart_echo_simple.c
2013-06-12 19:43:10 -07:00

67 lines
1.9 KiB
C

/*
* This file is part of the libopencm3 project.
*
* Copyright (C) 2011 Gareth McMullin <gareth@blacksphere.co.nz>
* Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
*
* This library is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#include <libopencm3/lm4f/systemcontrol.h>
#include <libopencm3/lm4f/gpio.h>
#include <libopencm3/lm4f/uart.h>
static void uart_setup(void)
{
/* Enable GPIOA in run mode. */
periph_clock_enable(RCC_GPIOA);
/* Mux PA0 and PA1 to UART0 (alternate function 1) */
gpio_set_af(GPIOA, 1, GPIO0 | GPIO1);
/* Enable the UART clock */
periph_clock_enable(RCC_UART0);
/* We need a brief delay before we can access UART config registers */
__asm__("nop");
/* Disable the UART while we mess with its setings */
uart_disable(UART0);
/* Configure the UART clock source as precision internal oscillator */
uart_clock_from_piosc(UART0);
/* Set communication parameters */
uart_set_baudrate(UART0, 921600);
uart_set_databits(UART0, 8);
uart_set_parity(UART0, UART_PARITY_NONE);
uart_set_stopbits(UART0, 1);
/* Now that we're done messing with the settings, enable the UART */
uart_enable(UART0);
}
int main(void)
{
uint8_t rx;
gpio_enable_ahb_aperture();
uart_setup();
/*
* Yes, it's that simple !
*/
while(1) {
rx = uart_recv_blocking(UART0);
uart_send_blocking(UART0, rx);
}
return 0;
}