構造体定義書

A Transmit Command Block & TBD. Must be

struct ifec_tcb

No.	名称	属性	説明
1	ifec_tcb		A Transmit Command Block & TBD. Must be
	status	volatile s16	word (even address) aligned
	command	u16
	link	u32	PHYSICAL next ifec_tcb, doesn't change
	tbda_addr	u32	TBD Array, points to TBD below
	count	s32	# of TBD, Tx start thresh., etc.
	tbd_addr0	u32	PHYSICAL ptr to Tx data
	tbd_size0	s32	Length of Tx data
	iob	io_buffer *	Exists from tx() to completion poll()
	next	ifec_tcb *	VIRTUAL next ifec_tcb, doesn't change

ifec_tcb