Toshiba TLCS-900/H1 Series Manual page 426

3.19 Touch Screen Interface (TSI)
The TMP92CH21 has an interface for a 4-terminal resistor network touch screen.
This interface supports two procedures: an X/Y position measurement and touch detection.
Each procedure is executed by setting the TSI control register (TSICR0 and TSICR1) and
using an internal AD converter.
3.19.1 Touch Screen Interface Module Internal/External Connection
X+
AVCC
AVSS
P97
(PY)
P96/INT4
(PX)
PXD (typ.200 kΩ)
PG3/AN3
(MY)
PG2/AN2
(MX)
VREFH
VREFL
Y−
Touch
X−
screen
Y+
External capacitors
Figure 3.19.1 External Connection of TSI
SPY SPX
SMX SMY
Figure 3.19.2 Internal Block Diagram of TSI
92CH21-424
TMP92CH21
MY
MX
PY
PX
Touch screen control
PXEN
Dec. PYEN
MXEN
MYEN
TSI7
AD converter
AN3
AN2
AVCC
AVSS
VREFH
VREFL
TMP92CH21
INT4
PTST
2009-06-19