3M
™ Multi-Touch ASIC Controller Reference Guide
23
3M Touch Systems, Inc. Proprietary Information
Asynchronous Reports
Depending on the firmware, one of these two reports will be sent
when using this feature.
These are used to transfer the coordinate data to the host. One of these reports,
depending of the particular firmware used, is sent to the host whenever new data is
available or scheduled for transmission.
Of the two reports, report 0x13 can hold up to 6 simultaneous touches while report 0x17
supports up to 10 simultaneous touches. Note that if there are more than a report can
hold, multiple reports are sent as many times as necessary to accommodate the number of
fingers touching. Only the first report of a set will have a non-zero actual count. Each
valid touch is marked with an ID number that remains the same from touchdown through
liftoff. The ID number can be any value from 0 to 255. Ignore all other data within a
touch report structure with a status marked “not valid”. The coordinate system's origin is
in the upper left corner of the touch screen, consistent with most operating systems'
coordinate systems.
Table 21. Coordinate Data Report 0x13 Data Stage
Offset Field
Size Value
Description
0
Report ID
1
0x13
Report ID
1
Touch Report
10
See Table 22
Touch Report Structure
11
Touch Report
10
See Table 22
Touch Report Structure
21
Touch Report
10
See Table 22
Touch Report Structure
31
Touch Report
10
See Table 22
Touch Report Structure
41
Touch Report
10
See Table 22
Touch Report Structure
51
Touch Report
10
See Table 22
Touch Report Structure
61
Actual Count
1
1 to max
Number of valid touch reports
(no more than declared max
touch reports)
62
Not used
1
0
63
Not used
1
0
Table 22. Touch Report Structure for Report 0x13
Offset
Field
Size Value
Description
0
Status
6
0xXX
0x00 Report not valid
0x04 Not touching
0x07 Touching
1
Touch ID
1
0-255
Not used
2
X lsb
1
0xXX
X ( 0-7FFF)
3
X msb
1
0xXX
4
Y lsb
1
0xXX
Y ( 0-7FFF)
5
Y msb
1
0xXX
