Lucent Technologies USS-720 - Manual (Page 86)

7-28 Lucent Technologies Inc.
USS-720 Preliminary User Guide, Rev. 2
USB Device Driver February 1999
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4 I/O Control Codes (continued)
4.19 IOCTL_SET_1284_REGISTER
IOCTL_SET_1284_REGISTER sets one of the 1284 registers. Details regarding parameters and error codes
follow.
4.19.1 Parameters
lpInBuffer—Points to an input buffer that contains the following 2 bytes:
nInBufferSize—Specifies the size (in bytes) of the buffer pointed to by lpInBuffer . For this operation, this value
should be 2.
lpOutBuffer—Points to an output buffer. Not used with this operation. Set to NULL.
nOutBufferSize—Specifies the size (in bytes) of the buffer pointed to by lpOutBuffer. Not used with this operation.
Set to zero.
lpBytesReturned—Points to a DWORD that receives the actual size (in bytes) of the data stored into lpOutBuffer.
Not used with this operation.
4.19.2 Notes
See USS-720 USB-to-IEEE 1284 Bridge Preliminary Data Sheet, for more detail on the vendor-specific requests
SET_1284_REGISTER.
4.19.3 Error Codes
ERROR_INVALID_ALTERNATESETTING—This command is only supported in ALT_INTERFACE_2 (see
Section 4.9 of this document).
ERROR_INVALID_ADDRESS_REGISTER—Address of the parallel port register is read only.
STATUS_INSUFFICIENT_RESOURCES—Not enough memory to perform the request on this device instance.
Byte Description
0 Value to be written to the register.
1 Address of the parallel port register.