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make variables static

This commit is contained in:
King Kévin 2016-01-18 16:12:42 +01:00
parent 41f0f7d7b4
commit 8b8b2bf287
2 changed files with 13 additions and 12 deletions
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21
lib/usart.c
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@ -25,16 +25,17 @@
#include <libopencm3/stm32/gpio.h> // general purpose input output library #include <libopencm3/stm32/gpio.h> // general purpose input output library
#include <libopencm3/stm32/usart.h> // universal synchronous asynchronous receiver transmitter library #include <libopencm3/stm32/usart.h> // universal synchronous asynchronous receiver transmitter library
#include <libopencm3/cm3/nvic.h> // interrupt handler #include <libopencm3/cm3/nvic.h> // interrupt handler
#include <libopencmsis/core_cm3.h> // Cortex M3 utilities
#include "usart.h" // USART header and definitions #include "usart.h" // USART header and definitions
/* input and output ring buffer, indexes, and available memory */ /* input and output ring buffer, indexes, and available memory */
uint8_t rx_buffer[USART_BUFFER] = {0}; static uint8_t rx_buffer[USART_BUFFER] = {0};
volatile uint8_t rx_i = 0; static volatile uint8_t rx_i = 0;
volatile uint8_t rx_used = 0; static volatile uint8_t rx_used = 0;
uint8_t tx_buffer[USART_BUFFER] = {0}; static uint8_t tx_buffer[USART_BUFFER] = {0};
volatile uint8_t tx_i = 0; static volatile uint8_t tx_i = 0;
volatile uint8_t tx_used = 0; static volatile uint8_t tx_used = 0;
/* show the user how much data received over USART is ready */ /* show the user how much data received over USART is ready */
volatile uint8_t usart_received = 0; // same as rx_used, but since the user can write this variable we don't rely on it volatile uint8_t usart_received = 0; // same as rx_used, but since the user can write this variable we don't rely on it
@ -79,7 +80,7 @@ void usart_putchar_blocking(char c)
void usart_flush(void) void usart_flush(void)
{ {
while (tx_used) { // idle until buffer is empty while (tx_used) { // idle until buffer is empty
__asm__("wfi"); // sleep until interrupt __WFI(); // sleep until interrupt
} }
usart_wait_send_ready(USART); // wait until transmit register is empty (transmission might not be complete) usart_wait_send_ready(USART); // wait until transmit register is empty (transmission might not be complete)
} }
@ -88,7 +89,7 @@ void usart_flush(void)
char usart_getchar(void) char usart_getchar(void)
{ {
while (!rx_used) { // idle until data is available while (!rx_used) { // idle until data is available
__asm__("wfi"); // sleep until interrupt; __WFI(); // sleep until interrupt;
} }
char to_return = rx_buffer[rx_i]; // get the next available character char to_return = rx_buffer[rx_i]; // get the next available character
rx_i = (rx_i+1)%sizeof(rx_buffer); // update used buffer rx_i = (rx_i+1)%sizeof(rx_buffer); // update used buffer
@ -97,11 +98,11 @@ char usart_getchar(void)
return to_return; return to_return;
} }
/* put character on USART stream (non-blocking using a buffer) */ /* put character on USART (non-blocking until buffer is full) */
void usart_putchar_nonblocking(char c) void usart_putchar_nonblocking(char c)
{ {
while (tx_used>=sizeof(tx_buffer)) { // idle until buffer has some space while (tx_used>=sizeof(tx_buffer)) { // idle until buffer has some space
__asm__("wfi"); __WFI();
} }
tx_buffer[(tx_i+tx_used)%sizeof(tx_buffer)] = c; // put character in buffer tx_buffer[(tx_i+tx_used)%sizeof(tx_buffer)] = c; // put character in buffer
tx_used++; // update used buffer tx_used++; // update used buffer

4
lib/usart.h
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@ -25,8 +25,8 @@
/* serial baudrate, in bits per second (with 8N1 8 bits, no parity bit, 1 stop bit settings) */ /* serial baudrate, in bits per second (with 8N1 8 bits, no parity bit, 1 stop bit settings) */
#define BAUD 115200 #define BAUD 115200
/* USART RX and TX buffer sizes */ /* RX and TX buffer sizes */
#define USART_BUFFER 64 #define USART_BUFFER 128
/* show the user how much received is available */ /* show the user how much received is available */
extern volatile uint8_t usart_received; extern volatile uint8_t usart_received;