_AHDLCDCB Struct Reference

#include <dev/ahdlc.h>

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Detailed Description

Asynchronous HDLC device information structure.

The start of this structure is equal to the UARTDCB structure.

Data Fields
u_long	dcb_modeflags
	Mode flags.
u_long	dcb_statusflags
	Status flags.
u_long	dcb_rtimeout
	Read timeout.
u_long	dcb_wtimeout
	Write timeout.
HANDLE	dcb_tx_rdy
	Queue of threads waiting for output buffer empty.
HANDLE	dcb_rx_rdy
	Queue of threads waiting for a character in the input buffer.
u_char	dcb_base
	Hardware base address.
volatile u_char *	dcb_rx_buf
	Input buffer.
volatile u_char	dcb_rx_idx
	Input buffer index for next incoming byte.
u_char	dcb_rd_idx
	Input buffer index for next byte to read.
u_char *	dcb_tx_buf
	Output buffer.
volatile u_char	dcb_tx_idx
	Output buffer index for next outgoing byte.
u_char	dcb_wr_idx
	Output buffer index for next byte to write.
HANDLE	dcb_mf_evt
	HDLC mode change event queue.
u_long	dcb_rx_accm
	32-bit receive ACCM.
u_long	dcb_tx_accm
	256-bit transmit ACCM.
u_short	dcb_rx_mru
	Maximum receive MRU.
u_short	dcb_tx_mru
	Maximum transmit MRU.

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Field Documentation

HANDLE _AHDLCDCB::dcb_tx_rdy

Queue of threads waiting for output buffer empty. Threads are added to this queue when the output buffer is full or when flushing the output buffer.

HANDLE _AHDLCDCB::dcb_rx_rdy

Queue of threads waiting for a character in the input buffer. Threads are added to this queue when the output buffer is empty.

u_char _AHDLCDCB::dcb_base

Hardware base address. This is a copy of the base address in the NUTDEVICE structure and required by the interrupt routine.

volatile u_char* _AHDLCDCB::dcb_rx_buf

Input buffer. This buffer is filled by the the receiver interrupt, so the contents of the buffer is volatile.

volatile u_char _AHDLCDCB::dcb_rx_idx

Input buffer index for next incoming byte. This volatile index is incremented by the receiver interrupt.

volatile u_char _AHDLCDCB::dcb_tx_idx

Output buffer index for next outgoing byte. This volatile index is incremented by the transmit interrupt.

HANDLE _AHDLCDCB::dcb_mf_evt

HDLC mode change event queue. The frame receiver thread is waiting on this queue until the device is switched to HDLC mode.

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