Usbio device and pipe objects example – Motorola USB08 User Manual

Page 143

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Universal USB Device Driver (USBIO)

Architecture

USB08 Evaluation Board

Designer Reference Manual

MOTOROLA

Universal USB Device Driver (USBIO)

143

Figure E-2. USBIO Device and Pipe Objects Example

The device object is identified by a device name as described in

E.4.1.1 USBIO Device Objects

. A pipe object is identified by its

endpoint address that also includes the direction flag at bit 7 (MSB). Pipe
0x81 is an IN pipe (transfer direction from device to host) and pipe 0x02
is an OUT pipe (transfer direction from host to device). The application
has created three handles for the device by calling

CreateFile()

.

Handle1 is not bound to any pipe, therefore it can be used to perform
device-related operations only. It is called a device handle.

Handle2 is bound to the IN pipe 0x81. By using this handle with the
Win32 function

ReadFile()

the application can initiate data transfers

from endpoint 0x81 to its buffers.

Handle3 is bound to the OUT pipe 0x02. By using Handle3 with the
function

WriteFile()

the application can initiate data transfers from its

buffers to endpoint 0x02 of the device.

User Mode

Kernel Mode

Handle1

Handle2

Handle3

Application

Device Object

identified by device name

Pipe 0x81

Pipe 0x02

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