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Diffstat (limited to 'examples/stm32/f1/stm32-h103/usart_irq/usart_irq.c')
-rw-r--r--examples/stm32/f1/stm32-h103/usart_irq/usart_irq.c119
1 files changed, 119 insertions, 0 deletions
diff --git a/examples/stm32/f1/stm32-h103/usart_irq/usart_irq.c b/examples/stm32/f1/stm32-h103/usart_irq/usart_irq.c
new file mode 100644
index 0000000..a2d8eef
--- /dev/null
+++ b/examples/stm32/f1/stm32-h103/usart_irq/usart_irq.c
@@ -0,0 +1,119 @@
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <libopencm3/stm32/f1/rcc.h>
+#include <libopencm3/stm32/f1/gpio.h>
+#include <libopencm3/stm32/usart.h>
+#include <libopencm3/stm32/nvic.h>
+
+void clock_setup(void)
+{
+ rcc_clock_setup_in_hse_8mhz_out_72mhz();
+
+ /* Enable GPIOA clock (for LED GPIOs). */
+ rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPCEN);
+
+ /* Enable clocks for GPIO port A (for GPIO_USART1_TX) and USART1. */
+ rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPAEN |
+ RCC_APB2ENR_AFIOEN |
+ RCC_APB2ENR_USART1EN);
+}
+
+void usart_setup(void)
+{
+ /* Enable the USART1 interrupt. */
+ nvic_enable_irq(NVIC_USART1_IRQ);
+
+ /* Setup GPIO pin GPIO_USART1_RE_TX on GPIO port B for transmit. */
+ gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ,
+ GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART1_TX);
+
+ /* Setup GPIO pin GPIO_USART1_RE_RX on GPIO port B for receive. */
+ gpio_set_mode(GPIOA, GPIO_MODE_INPUT,
+ GPIO_CNF_INPUT_FLOAT, GPIO_USART1_RX);
+
+ /* Setup UART parameters. */
+ usart_set_baudrate(USART1, 230400, rcc_ppre2_frequency);
+ usart_set_databits(USART1, 8);
+ usart_set_stopbits(USART1, USART_STOPBITS_1);
+ usart_set_parity(USART1, USART_PARITY_NONE);
+ usart_set_flow_control(USART1, USART_FLOWCONTROL_NONE);
+ usart_set_mode(USART1, USART_MODE_TX_RX);
+
+ /* Enable USART1 Receive interrupt. */
+ USART_CR1(USART1) |= USART_CR1_RXNEIE;
+
+ /* Finally enable the USART. */
+ usart_enable(USART1);
+}
+
+void gpio_setup(void)
+{
+ gpio_set(GPIOC, GPIO12);
+
+ /* Setup GPIO6 and 7 (in GPIO port A) for led use. */
+ gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ,
+ GPIO_CNF_OUTPUT_PUSHPULL, GPIO12);
+}
+
+void usart1_isr(void)
+{
+ static u8 data = 'A';
+
+ /* Check if we were called because of RXNE. */
+ if (((USART_CR1(USART1) & USART_CR1_RXNEIE) != 0) &&
+ ((USART_SR(USART1) & USART_SR_RXNE) != 0)) {
+
+ /* Indicate that we got data. */
+ gpio_toggle(GPIOC, GPIO12);
+
+ /* Retrieve the data from the peripheral. */
+ data = usart_recv(USART1);
+
+ /* Enable transmit interrupt so it sends back the data. */
+ USART_CR1(USART1) |= USART_CR1_TXEIE;
+ }
+
+ /* Check if we were called because of TXE. */
+ if (((USART_CR1(USART1) & USART_CR1_TXEIE) != 0) &&
+ ((USART_SR(USART1) & USART_SR_TXE) != 0)) {
+
+ /* Indicate that we are sending out data. */
+ //gpio_toggle(GPIOA, GPIO7);
+
+ /* Put data into the transmit register. */
+ usart_send(USART1, data);
+
+ /* Disable the TXE interrupt as we don't need it anymore. */
+ USART_CR1(USART1) &= ~USART_CR1_TXEIE;
+ }
+}
+
+int main(void)
+{
+ clock_setup();
+ gpio_setup();
+ usart_setup();
+
+ /* Wait forever and do nothing. */
+ while (1)
+ __asm__("nop");
+
+ return 0;
+}