W99681CF Datasheet, PDF (27/78 Pages) Winbond – JPEG USB Dual Mode Camera Chip

W99681CF
7.4 USB Interface and Device Control
The W99681CF contains two endpoints: default and Video Data-In endpoints. Figure 7.3 shows the
device configuration for the W99681CF-based USB digital video camera.
Host
Default Pipe
Data-In Pipe
W9967CF-Based
Device
Figure 7.3 Device Configuration
7.4.1 Endpoints
7.4.1.1 Default Endpoint (Endpoint 0)
The default endpoint uses control transfers as defined in the USB specification. The default endpoint
provides access to the W99681CF-based device′s configuration, status, and control information by
sending standard, class, and vendor-specific requests to the device, an interface, or an endpoint.
7.4.1.2 Video Data-In Endpoint (Endpoint 1)
The Video Data-In endpoint is used to receive video image data from the device intended for delivery to
a video capture application on the host. The Video Data-In endpoint uses isochronous transfers. The
direction is always IN. The maximum packet size can be varied for different alternate settings for limited
USB bandwidth.
7.4.2 USB Device Requests
The W99681CF responds to requests from the host on the default pipe. The W99681CF supports
standard, class, and vendor-specific USB device requests.
7.4.2.1 Standard Device Requests
The W99681CF supports the standard USB device requests as shown in Table 7.3 and described
below. It responds to standard device requests whether it has been assigned a non-default address or
is currently configured. If any unrecognized or unsupported standard request is received, it returns
STALL.
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Publication Release Date: March 2000
Revision A1