AR1100 Datasheet, PDF (17/58 Pages) Microchip Technology – AR1100 Resistive USB and RS-232 Touch Screen Controller

AR1100 RESISTIVE USB AND RS-232 TOUCH SCREEN CONTROLLER
4.2.1.3 Mode: HID-DIGITIZER
Touch report format:
TABLE 4-5: TOUCH REPORT FORMAT – DIGITIZER
BYTE
BIT
7
6
5
4
3
2
1
0
1
0
0
0
0
0
0
P
T
2
0
0
0
0
0
0
0
0
3
X7
X6
X5
X4
X3
X2
X1
X0
4
0
0
0
0
X11
X10
X9
X8
5
Y7
Y6
Y5
Y4
Y3
Y2
Y1
Y0
6
0
0
0
0
Y11
Y10
Y9
Y8
T
Tip switch
P
Proximity (in range) – always 1
X
X ordinate of touch location (12 bits)
Y
X ordinate of touch location (12 bits)
For flexibility, the value and behavior of the ‘tip switch’
data entity (“T”) and touch reporting react to and is
defined by the ‘Touch mode’ parameter (similar to ‘pen
state’ bit in HID-GENERIC or UART).
TABLE 4-6:
MODE
0
1
2
3
4
5
PD
PU
PM
Report
TOUCH MODE OPTIONS – DIGITIZER
SUPPORTED EVENT
PD
PU
PM
BEHAVIOR
X
X
X
X
X
X
X
X
X
X
X
X
Pen down
Pen up
Pen move
Touch report
X
NO REPORT
X
REPORT (T=0)
X
REPORT (T=1)
X
REPORT (T=1), REPORT (T=0)
REPORT (T=0), REPORT (T=1), REPORT (T=0)
REPORT (T=0), REPORT (T=1)
4.2.2 COMMAND PACKETS
PACKETs are used for all communications, other than
touch reports (i.e., configuration/control). COMMAND
packets (issued by the host) and RESPONSE packets
(issued by the device) have identical framework but dif-
fer slightly in format, as described below. In standard
operation, communication is initiated by the host then
acknowledged by the device. In some diagnostic sce-
narios (not discussed here) – a COMMAND packet
does not necessarily dictate a response from the
device and, in other cases, a RESPONSE packet may
be issued by the device unsolicited.
 2011 Microchip Technology Inc.
DS41606B-page 17