Lucent Technologies USS-720 manual IOCTLGET1284REGISTER

Preliminary User Guide, Rev. 2	USS-720
February 1999	USB Device Driver

4 I/O Control Codes (continued)

4.8 IOCTL_GET_1284_REGISTER

IOCTL_GET_1284_REGISTER returns all 1284 registers. Details regarding parameters and error codes follow.

4.8.1 Parameters

lpInBuffer—Points to an input buffer that contains a byte that specifies the address of the parallel port register to be read.

nInBufferSize—Specifies the size (in bytes) of the buffer pointed to by lpInBuffer. This buffer must be large enough to contain one byte value.

lpOutBuffer—Points to an output buffer that will receive a REGISTER_1284 structure or an ADVREGISTER_1284 structure (see Sections 5.3 and 5.4 of this document).

nOutBufferSize—Specifies the size (in bytes) of the buffer pointed to by lpOutBuffer, which must be large enough to contain a REGISTER_1284 data structure or an ADVREGISTER_1284 structure. The size specified in nOutBuffer- Size will determine whether REGISTER_1284 or ADVREGISTER_1284 is returned (see Sections 5.3 and 5.4 of this document).

lpBytesReturned—Points to a DWORD that receives the actual size (in bytes) of the data stored into lpOutBuffer.

4.8.2 Notes

See the USS-720USB-to-IEEE 1284 Bridge Preliminary Data Sheet, “GET_1284_REGISTER” for more details on the vendor-specific requests.

4.8.3 Error Codes

ERROR_INVALID_ALTERNATESETTING—This command is only supported in ALT_INTERFACE_2 (see Section 4.9 of this document).

ERROR_NOT_ENOUGH_BUFFER—lpOutBuffer needs to be large enough to receive a REGISTER_1284 struc- ture (see Section 5.3 of this document).

STATUS_INSUFFICIENT_RESOURCES—Not enough memory to perform the request on this device instance.

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