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Download GCX Graphics ClientX User`s Manual
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GCX User’s Manual 6.4.14 PXA255 Processor The XScale PXA255 core can change system voltage Vddi (6.4.1) dynamically to achieve lower power consumption at high clock rates. It uses voltage Vddx to power its interface I/Os. The digital I/Os include series resistance and ESD protection. Serial ports configured for 3.3 V logic operation run directly to the processor (section 4.5.1). These lines should be treated as digital I/Os and protected for over-current and over-voltage accordingly. Absolute Maximum Ratings Input voltage, digital I/O pins.....................................3.6 V Symbol Parameter Min Digital Outputs Vol Voh Io Digital Inputs Vil Vih NSSP Port Max Units 2 V V mA 0 3.3 -2 0.2 0.8 Base bit rate, internal clock Divisor for Internal clock Clock rate, external source 6.4.15 Typ. 3.6864 1 Vddx Vddx MHz 4096 13 MHz Crystal Frequencies Agencies certifying the GCX for compliance for radio-frequency emissions typically need to know the frequencies of onboard oscillators. The following table lists the frequencies of all crystals on the GCX. Crystal X1 X2 X3 X4 X5 X6 X7 Page 58 Device Ethernet ADSmartIO microcontroller XScale core XScale real-time clock (RTC) CAN controller Battery-backed RTC UCB1400 codec Typ. Units 25.000 3.6864 3.6864 32.768 16.000 32.768 24.576 MHz MHz MHz kHz MHz kHz MHz ADS document # 110116-10012
