Lantronix DSTni-EX manual 4. BDT Data Used by USB Controller and Microprocessor

Table 4-4. BDT Data Used by USB Controller and Microprocessor

USB Controller Determines…	Microprocessor Determines…
Who owns the buffer in system memory	Who owns the buffer in system memory
Data0 or Data1 PID	Data0 or Data1 PID
Release Own upon packet completion
No address increment (FIFO Mode)
Data Toggle Synchronization enable
Amount of data to be transmitted or received	Amount of data transmitted or received
Where the buffer resides in system memory	Where the buffer resides in system memory

Table 4-5shows the USB BD format.

Table 4-5. USB Buffer Descriptor Format

	7	6		5			4	3	2		1		0
	OWN	DATA0/1		USB_OWN			NINC	DTS	RSVD	0		0
						0
						BC[7:0]
			0								BCH9		BCH8
Low Byte					ADDR[7:0]
Byte 2					ADDR[15:8]
Byte 3				ADDR[23:16]
Byte 4				ADDR[31:24]

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