ucb1400 NXP Semiconductors, ucb1400 Datasheet - Page 29

• Manufacturer Part Number: ucb1400
• Description: Audio Codec With Touch Screen Controller And Power Management Monitor
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Table 9:
[1]
[2]
9397 750 09611
Product data
Touch screen
measurement
X position
Y position
Pressure - 1
Pressure - 2
Pressure - 3
Pressure - 4
Pressure - 5
X plate resistance
Y plate resistance
Interrupt
For X and Y position measurements, (PXP, PXG, PYP, PYG) can be swapped with (MXP, MXG, MYP, MYG) to get readings reversed in
direction.
For pressure measurements, (PXP, PXG, PYP, PYG) can be swapped with (MXP, MXG, MYP, MYG) to get the same readings with
current flowing in the opposite direction.
[1]
[1]
Measurement mode summary
[2]
[2]
[2]
[2]
[2]
10.2.5 Mode summary
PXP
1
0
1
1
0
0
0
1
0
1
In addition to the measurements made above, the touch screen can also act as an
interrupt source. In this mode, the X plate of the touch screen has to be powered, and
the Y plate has to be grounded. In this case, the touch screen is not biased by the
active touch screen bias circuit, but by a resistor to AV
biases the touch screen and the UCB1400 does not consume power unless the touch
screen is touched. The voltage on the X plate terminals drops if the screen is
pressed. This voltage drop is detected by Schmitt trigger circuits, of which the outputs
are connected to the interrupt control block. A touch screen interrupt is generated
either when the touch screen is pressed (falling edge enabled) or when the touch
screen is released (rising edge enabled), which can be used to activate the system
around the UCB1400 to start a touch screen readout sequence. The internal Schmitt
trigger circuits are connected to the TSPX and TSMX signals after the built-in
low-pass filters. This reduces the number of spurious interrupts, due to the coupling
between the LCD screen and the touch screen sensors.
PXG
0
0
0
0
0
0
1
0
0
0
MXP
0
0
1
0
0
1
0
0
0
1
MXG
1
0
0
0
1
0
0
1
0
0
Rev. 02 — 21 June 2002
PYP
0
1
0
0
1
0
0
0
1
0
PYG
0
0
1
1
0
0
0
0
0
1
Audio codec with touch screen controller
MYP
0
0
0
0
0
0
1
0
0
0
and power management monitor
MYG
0
1
1
0
0
1
0
0
1
1
© Koninklijke Philips Electronics N.V. 2002. All rights reserved.
DD
. This configuration simply
BIAS
1
1
1
1
1
1
1
1
1
0
UCB1400
TM
2
2
1
1
1
1
1
1
1
0
AI
2 or 3
0 or 1
Any
Any
Any
Any
Any
Any
Any
Any
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