SAM9G45 Atmel Corporation, SAM9G45 Datasheet - Page 921

• Manufacturer Part Number: SAM9G45
• Manufacturer: Atmel Corporation

Specifications of SAM9G45

• Flash (kbytes): 0 Kbytes
• Pin Count: 324
• Max. Operating Frequency: 400 MHz
• Cpu: ARM926
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 160
• Ext Interrupts: 160
• Usb Transceiver: 3
• Usb Speed: Hi-Speed
• Usb Interface: Host, Device
• Spi: 2
• Twi (i2c): 2
• Uart: 5
• Lin: 4
• Ssc: 2
• Ethernet: 1
• Sd / Emmc: 2
• Graphic Lcd: Yes
• Video Decoder: No
• Camera Interface: Yes
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 440
• Resistive Touch Screen: Yes
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 64
• Self Program Memory: NO
• External Bus Interface: 2
• Dram Memory: DDR2/LPDDR, SDRAM/LPSDR
• Nand Interface: Yes
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8/3.3
• Operating Voltage (vcc): 0.9 to 1.1
• Fpu: No
• Mpu / Mmu: No/Yes
• Timers: 6
• Output Compare Channels: 6
• Input Capture Channels: 6
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: No

41.7.4
11053B–ATARM–22-Sep-11
4-wire Pressure Measurement Method
It is possible to correct for switch loss by performing the operation:
This requires additional measurements, as shown in
Figure 41-6. Touchscreen Switches Implementation
The method to measure the pressure (Rp) applied to the touchscreen is based on the known
resistance of the X-Panel resistance (Rxp).
Three conversions (Xpos,Z1,Z2) are necessary to determine the value of Rp (Zaxis resistance).
Rp = Rxp*(Xpos/1024)*[(Z2/Z1)-1]
[VY
P
- VX
M
Horizontal Position Detection
] / [VX
X
X
VDDANA
M
P
P
GND
X
Y
- VX
X
Y
M
M
P
P
Resistor
M
Switch
Resistor
Switch
].
Y
P
VDDANA
VDDANA
GND
GND
Figure
0
1
2
3
Vertical Position Detection
Y
41-6.
Y
VDDANA
M
P
GND
To the ADC
Resistor
Switch
Resistor
Switch
X
SAM9G35
P
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