EP9315-IBZ Cirrus Logic Inc, EP9315-IBZ Datasheet - Page 746

• Manufacturer Part Number: EP9315-IBZ
• Description: 32-Bit Microcontroller IC
• Manufacturer: Cirrus Logic Inc
• Series: EP9r

Specifications of EP9315-IBZ

• Controller Family/series: (ARM9)
• Core Size: 32 Bit
• A/d Converter: 12 Bits
• Supply Voltage: 3.3V
• No. Of I/o Pins: 65
• Package / Case: 352-PBGA
• Clock Frequency: 200MHz
• Core Processor: ARM9
• Speed: 200MHz
• Connectivity: EBI/EMI, EIDE, Ethernet, I²C, IrDA, Keypad/Touchscreen, PCMCIA, SPI, UART/USART, USB
• Peripherals: AC'97, DMA, I&sup2:S, LCD, LED, MaverickKey, POR, PWM, WDT
• Number Of I /o: 16
• Program Memory Type: ROMless
• Ram Size: 32K x 8
• Voltage - Supply (vcc/vdd): 1.65 V ~ 3.6 V
• Data Converters: A/D 8x12b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Processor Series: EP93xx
• Core: ARM920T
• Data Bus Width: 32 bit
• 3rd Party Development Tools: MDK-ARM, RL-ARM, ULINK2
• Development Tools By Supplier: EDB9315A-Z
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 598-1144 - KIT DEVELOPMENT EP9315 ARM9
• Eeprom Size: -
• Program Memory Size: -
• Lead Free Status / Rohs Status: Details
• Other names: 598-1263

25
25-8
Analog Touch Screen Interface
EP93xx User’s Guide
The difference between this new X value and the last valid X value is then compared against
the XMIN value stored in the TSXYMaxMin register (unless the X interrupt pending flag is
set). If the difference is less than this value no action is taken, and the algorithm continues by
discharging and scanning the Y-axis. If the difference between the new X value and the last X
value is greater than the XMIN value, the algorithm continues by comparing the difference
between the new X value and the last X value to the XMAX value in the TSXYMaxMin
register. If the difference is greater than XMAX, it is assumed that this distance is too far for a
touch input to possibly move in the short scan time interval and that the key press is invalid.
However, it is stored as the last recorded X location in case a truly new location is being
determined. The X move interrupt pending flag is also set at this point to cause the algorithm
to skip over the comparison to XMIN on consecutive sample sets. This flag will also cause a
ARM Core interrupt after valid X and Y samples have been established.
The algorithm then starts again, discharging and detecting a valid press. If the difference
between the new X value and the last stored X value is less than the XMAX value, the
algorithm stores the new X value, sets the X move interrupt pending flag and continues by
discharging and scanning a Y-axis value.
scanning process.
The Y-axis scan proceeds in the same fashion as the X-axis scan, except that the switch
matrix is now controlled by the TSYSample register. When the new Y value has been
calculated, the difference between this new Y value and the last valid Y value is then
compared against the YMIN value stored in the TSXYMaxMin register (unless the Y interrupt
pending flag is set). If the difference is less than this value, no Y action is taken and the
algorithm continues by checking the X interrupt pending flag. If this flag is set the Y value is
stored in the Y last register and the interrupt to the ARM Core is generated.
Copyright 2007 Cirrus Logic
Figure 25-4
is the flow chart demonstrating the
DS785UM1