Datasheet

 2011 Microchip Technology Inc. DS41606B-page 17
AR1100 RESISTIVE USB AND RS-232 TOUCH SCREEN CONTROLLER
4.2.1.3 Mode: HID-DIGITIZER
Touch report format:
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).
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.
TABLE 4-5: TOUCH REPORT FORMAT – DIGITIZER
BYTE
BIT
76543210
1000000PT
200000000
3 X7 X6 X5X4X3X2X1X0
40000X11X10X9X8
5 Y7 Y6 Y5Y4Y3Y2Y1Y0
60000Y11Y10Y9Y8
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)
TABLE 4-6: TOUCH MODE OPTIONS – DIGITIZER
MODE
SUPPORTED EVENT
BEHAVIOR
PD PU PM
0 X X X NO REPORT
1 X X X REPORT (T=0)
2 X X X REPORT (T=1)
3 X X X REPORT (T=1), REPORT (T=0)
4 X X REPORT (T=0), REPORT (T=1), REPORT (T=0)
5 X X REPORT (T=0), REPORT (T=1)
PD Pen down
PU Pen up
PM Pen move
Report Touch report