Lucent Technologies USS-720 Vendor-Specific Requests, Preliminary Data Sheet, Rev, Instant USB

Preliminary Data Sheet, Rev. 5	USS-720	Instant USB
September 1999	USB-to-IEEE	1284 Bridge

USB Port (continued)

Vendor-Specific Requests

Vendor-specific requests supported by the USS-720.

Table 17. Vendor-Specific Requests

Label	bmRequestType	bRequest	wValue	wIndex	wLength	Data
GET_1284_REGISTER	11000000B	3	Address	Zero	7	Register Data
SET_1284_REGISTER	01000000B	4	Address Data	Zero	Zero	[None]

GET_1284_REGISTER

The high byte of the wValue field specifies the address of the register that is to be read. The USS-720 responds by returning the current values in all of the parallel port registers. This command is only supported in interface 0, alternate setting 2. Attempts to issue this command to alternate settings 0 or 1 will result in a stall.

SET_1284_REGISTER

The wValue field specifies the address of the parallel port register to be written in the high byte and the value to be written in the low byte. This command is only sup- ported in interface 0, alternate setting 2. Attempts to issue this command to alternate settings 0 or 1 will result in a stall.

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