Lucent Technologies USS-720 - Manual (Page 68)

7-10 Lucent Technologies Inc.
USS-720 Preliminary User Guide, Rev. 2
USB Device Driver February 1999
13
4 I/O Control Codes (continued)
4.1 IOCTL_1284_ ECP_FWDTOREV
IOCTL_1284_ECP_FWDTOREV negotiates the peripheral from forward idle to reverse while in ECP register
mode. Details regarding parameters and error codes follow.
4.1.1 Parameters
lpInBuffer—Points to an input buffer. Not used with this operation. Set to NULL.
nInBufferSize—Specifies the size (in bytes) of the buffer pointed to by lpInBuffer. Not used with this operation. Set
to zero.
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.
4.1.2 Notes
Requires that the register-based mode be successfully set to ECP_REGISTER_MODE or
ECP_RLE_REGISTER_MODE (see
USS-720 USB-to-IEEE 1284 Bridge Preliminary Data Sheet, “Register-Based
Operation” and Section 4.4, IOCTL_1284_SET_MODE, of this document).
4.1.3 Error Codes
ERROR_INVALID_ALTERNATESETTING—This command is only supported in ALT_INTERFACE_2 (see
Section 4.9 of this document).
STATUS_IO_DEVICE_ERROR—Negotiation failed.