SAM9RL64 Atmel Corporation, SAM9RL64 Datasheet - Page 830

• Manufacturer Part Number: SAM9RL64
• Manufacturer: Atmel Corporation

Specifications of SAM9RL64

• Flash (kbytes): 0 Kbytes
• Pin Count: 217
• Max. Operating Frequency: 240 MHz
• Cpu: ARM926
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 118
• Ext Interrupts: 118
• Usb Transceiver: 1
• Usb Speed: Hi-Speed
• Usb Interface: Device
• Spi: 1
• Twi (i2c): 2
• Uart: 5
• Ssc: 2
• Sd / Emmc: 1
• Graphic Lcd: Yes
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 6
• Adc Resolution (bits): 10
• Adc Speed (ksps): 220
• Resistive Touch Screen: Yes
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 64
• Self Program Memory: NO
• External Bus Interface: 1
• Dram Memory: sdram
• Nand Interface: Yes
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8/3.3
• Operating Voltage (vcc): 1.08 to 1.32
• Fpu: No
• Mpu / Mmu: No / Yes
• Timers: 3
• Output Compare Channels: 3
• Input Capture Channels: 3
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: No

Figure 43-2. Touch Screen Position Measurement
43.6.2
830
AT91SAM9R64/RL64
Position Measurement Method
As shown in
bottom. Due to the linear resistance of the film, there is a voltage gradient from top to bottom.
When a contact is performed on the screen, the voltage propagates at the point the two surfaces
come into contact with the second film. If the input impedance on the right and left electrodes
sense is high enough, the film does not affect this voltage, despite its resistive nature.
For the horizontal direction, the same method is used, but by applying supply from left to right.
The range depends on the supply voltage and on the loss in the switches that connect to the top
and bottom electrodes.
In an ideal world (linear, with no loss through switches), the horizontal position is equal to:
The proposed implementation with on-chip power switches is shown in
measurement at the output of the switch compensates for the switches loss.
It is possible to correct for the switch loss by performing the operation:
This requires additional measurements, as shown in
Vertical Position Detection
X
X
M
P
VY
[VY
M
P
Y
/ VDD or VY
- VX
M
Figure
Y
P
M
] / [VX
Volt
VDD
43-2, to detect the position of a contact, a supply is first applied from top to
GND
P
P
X
M
/ VDD.
- VX
Contact
Pen
M
] .
X
P
Horizontal Position Detection
Y
Y
M
P
Y
P
Figure
X
P
43-3.
Volt
VDD
GND
Figure
6289D–ATARM–3-Oct-11
43-3. The voltage