LUPXA255A0C200 Datasheet, PDF (30/40 Pages) Intel Corporation – Electrical, Mechanical, and Thermal Specification

Electrical Specifications
Note: The minimum duty cycle for an external signal driven into PEXTAL is 40/60.
4.7
4.7.1
Reset and Power AC Timing Specifications
The processor asserts the nRESET_OUT pin in one of several different modes:
• Power on
• Hardware reset
• Watchdog reset
• GPIO reset
• Sleep mode
The following sections provide the timing and specifications for the entry and exit of these modes.
Power-On Timing
The external voltage regulator and other power-on devices must provide the processor with a
specific sequence of power and resets to ensure proper operation. Figure 3, “Power-On Reset
Timing” on page 31, shows this sequence and is detailed in Table 15, “Power-On Timing
Specifications” on page 31.
On the processor, it is important that the power supplies be powered up in a certain order to avoid
high current situations. The required order is:
1. VCCQ
2. VCCN
3. VCC and PLL_VCC
On the processor, it is important that the VCCQ power supply be powered up before or at the same
time as the VCCN power supply. The VCC and PLL_VCC power supplies may be powered up
anytime within the specification shown in Figure 3 and Table 15.
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Intel® PXA255 Processor Electrical, Mechanical, and Thermal Specification