cdc.h File Reference

#include <stdint.h>
#include <stdbool.h>

Go to the source code of this file.

Macros
#define	CDC_WRITE_MAX_RETRIES   500u
	Maximum number of busy-retry attempts inside CDC_Write.

Functions
bool	CDC_Write (const uint8_t *data, uint16_t len)
	Push len bytes to the USB CDC IN endpoint.
bool	CDC_WriteString (const char *s)
	Convenience wrapper that pushes a NUL-terminated C string.

Macro Definition Documentation

CDC_WRITE_MAX_RETRIES

#define CDC_WRITE_MAX_RETRIES   500u

Maximum number of busy-retry attempts inside CDC_Write.

Each retry sleeps one OS tick (task_active_sleep(1)), so the upper bound on a single CDC_Write call is roughly CDC_WRITE_MAX_RETRIES ticks. Default 500 → about 0.5 s at the kernel's 1 ms tick.

Definition at line 47 of file cdc.h.

Function Documentation

CDC_Write()

bool CDC_Write	(	const uint8_t *	data,
		uint16_t	len
	)

Push len bytes to the USB CDC IN endpoint.

Parameters

data	Pointer to the bytes to send (must be non-NULL when len > 0).
len	Number of bytes to send.

Returns

true if the bytes were accepted by the CDC stack within CDC_WRITE_MAX_RETRIES busy-retries; false otherwise (caller's bytes were not sent).

Note

Must be called from task context — the busy-retry path uses task_active_sleep(1) and would deadlock from an ISR.

The transmit buffer the ST middleware accepts is borrowed, not copied. The pointer data must remain valid until the function returns.

Definition at line 33 of file cdc.c.

References CDC_Transmit_FS(), CDC_WRITE_MAX_RETRIES, and task_active_sleep().

Referenced by CDC_WriteString().

CDC_WriteString()

bool CDC_WriteString

(

const char *

s

)

Convenience wrapper that pushes a NUL-terminated C string.

Parameters

s	NUL-terminated string. NULL is treated as a no-op success.

Returns

true on success, false if the underlying CDC_Write could not flush within the retry budget.

Definition at line 112 of file cdc.c.

References CDC_Write().