ATUC128L4U Atmel Corporation, ATUC128L4U Datasheet - Page 720

• Manufacturer Part Number: ATUC128L4U
• Manufacturer: Atmel Corporation

Specifications of ATUC128L4U

• Flash (kbytes): 128 Kbytes
• Pin Count: 48
• Max. Operating Frequency: 50 MHz
• Cpu: 32-bit AVR
• # Of Touch Channels: 17
• Hardware Qtouch Acquisition: Yes
• Max I/o Pins: 36
• Ext Interrupts: 36
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 1
• Twi (i2c): 2
• Uart: 4
• Lin: 4
• Ssc: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 12
• Adc Speed (ksps): 460
• Analog Comparators: 8
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 16
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.62 to 3.6
• Operating Voltage (vcc): 1.62 to 3.6
• Fpu: No
• Mpu / Mmu: Yes / No
• Timers: 6
• Output Compare Channels: 18
• Input Capture Channels: 12
• Pwm Channels: 35
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

29.7.3
32142A–12/2011
Resistive Touch Screen Pin Connections
Table 29-2.
The resistive touch screen film signals connects to the ADCIFB using the AD and ADP pins. The
X
(right) and Y
configurable through the Touch Screen Pin Offset (TSPO) field in the Mode Register (MR) and
allows the user to configure which AD pins to use for resistive touch screen applications. Writing
a zero to the TSPO field instructs the ADCIFB to use AD0 through AD3, where AD0 is con-
nected to X
ADCIFB to use AD1 through AD4 for resistive touch screen sequencing, where AD1 is con-
nected to X
When the Analog Pin Output Enable (APOE) bit in the Mode Register (MR) is zero, the AD pins
are used to measure input voltage and drive the GND sequences, while the ADP pins are used
to drive the VDD sequences. This arrangement allows the user to reduce the voltage seen at the
AD input pins by inserting external resistors between ADP0 and X
which are again directly connected to the AD pins. It is important that the voltages observed at
the AD pins are not higher than the maximum allowed ADC input voltage. See
page 721
ADP pins.
By adding a resistor between ADP0 and X
at the AD pins can be controlled by the following voltage divider expressions:
The Rfilmx parameter is the film resistance observed when measuring between X
Rresistorx parameter is the resistor size inserted between ADP0 and X
and Rresistory is the same but for ADP1, Y
ADCIFB Pin
ADP0
ADP1
ADtspo+0
ADtspo+1
ADtspo+2
ADtspo+3
P
(top) and X
for details regarding how to connect the resistive touch screen films to the AD and
P
P
M
, AD1 is connected to X
and AD0 is free to be used as an ordinary ADC channel.
M
Resistive Touch Screen Pin Connections
(left) signals are connected to ADtspo+2 and ADtspo+3 pins. The tspo index is
(bottom) film signals are connected to ADtspo+0 and ADtspo+1 pins, and the Y
V AD
tspo
TS Signal, APOE == 0
Xp through a resistor
Yp through a resistor
Xp
Xm
Yp
Ym
+
M
0
and so on. Writing a one to the TSPO field instructs the
=
-------------------------------------------- - V DP
R
P
P
, and ADP1 and Y
filmx
, and Y
R
+
filmx
R
M
resistorx
ATUC64/128/256L3/4U
instead.
P
, the maximum voltage observed
No Connect
No Connect
TS Signal, APOE == 1
Xp
Xm
Yp
Ym
0
P
and ADP1 and Y
P
. The definition of Rfilmy
Figure 29-3 on
P
and X
P
signals
M
. The
720
P