From c58c7dbe188509addf817dc208a234ddca6042fe Mon Sep 17 00:00:00 2001 From: Perry Hung Date: Wed, 4 Aug 2010 04:38:58 -0400 Subject: New usart implementation: Fixed a bug where the maximum baud rate was incorrectly set to 225000 General cleanup Use new rcc and nvic APIs --- libmaple/ring_buffer.h | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 libmaple/ring_buffer.h (limited to 'libmaple/ring_buffer.h') diff --git a/libmaple/ring_buffer.h b/libmaple/ring_buffer.h new file mode 100644 index 0000000..95b9dd8 --- /dev/null +++ b/libmaple/ring_buffer.h @@ -0,0 +1,57 @@ +/** + * @brief simple circular buffer + */ + +#ifndef _RING_BUFFER_H_ +#define _RING_BUFFER_H_ + +#ifdef __cplusplus +extern "C"{ +#endif + +/* The buffer is empty when head == tail. + * The buffer is full when the head is one byte in front of the tail + * The total buffer size must be a power of two + * One byte is left free to distinguish empty from full */ +typedef struct ring_buffer { + uint32 head; + uint32 tail; + uint8 size; + uint8 *buf; +} ring_buffer; + +static inline void rb_init(ring_buffer *rb, uint8 size, uint8 *buf) { + ASSERT(IS_POWER_OF_TWO(size)); + rb->head = 0; + rb->tail = 0; + rb->size = size; + rb->buf = buf; +} + +static inline void rb_insert(ring_buffer *rb, uint8 element) { + rb->buf[(rb->tail)++] = element; + rb->tail &= (rb->size - 1); +} + +static inline uint8 rb_remove(ring_buffer *rb) { + uint8 ch = rb->buf[rb->head++]; + rb->head &= (rb->size - 1); + return ch; +} + +static inline uint32 rb_full_count(ring_buffer *rb) { + return rb->tail - rb->head; +} + +static inline void rb_reset(ring_buffer *rb) { + rb->tail = rb->head; +} + +#ifdef __cplusplus +} // extern "C" +#endif + + + +#endif + -- cgit v1.2.3