[sane-devel] Trying to understand GL640
gmurray at cloudnet.com
Fri Aug 10 06:39:16 UTC 2007
The enum is probably from a different datasheet, possibly an earlier
A USB control message has an 8 byte setup packet with format
.. remainder of packet, if any, follows
The value shown in the enum is the value to be inserted into the "word value"
field above when sending a USB control message.
In the backend canon630u-common.c function gl640WriteControl uses
that enum value and inserts it into the field "value" and sends the USB
I did not see the USB control message discussed in that .pdf.
Do not confuse that enum and its values with the General Purpose
Registers (which actually exist in hardware) on page 10.
The USB control message is a structure of data bytes which
are in transport to/from host/device; it does not have hardware
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