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Download Elan(TM)SC520 Microcontroller Data Sheet
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A D V A N C E I N F O R M A T I O N CAPACITANCE Non-PCI Interface Pin Capacitance Advance Information Symbol CIN Parameter Description Test Conditions Input capacitance FC=1 MHz Min Max Unit — 10 pF C32KXTAL 32KXTAL1, 33KXTAL2 pin capacitance — 20 pF C33MXTAL 33MXTAL1, 33MXTAL2 pin capacitance — 15 pF COUT Output capacitance — 10 pF CIO I/O pin capacitance — 10 pF PCI Interface Pin Capacitance Derating Curves Pin capacitance values are specified in the PCI Local Bus Specification, Revision 2.2, section 4.2.2.1 DC Specifications, Table 4-3: DC Specifications for 3.3V Signaling. All programmable I/O pins can be driven to the maximum drive current at once. Crystal Capacitance The crystal specifications can be found in Table 8, “32.768-kHz Crystal Specifications” on page 42 and Table 9, “33-MHz Crystal Specifications” on page 42. The derating curves on the following pages can be used to determine potential specified timing variations based on system capacitive loading. Table 19, “Pin List Summary,” on page A-7 has a column named “Max Load (pF).” This column describes the specification load presented to the specific pin, when testing was performed, to generate the timing specification documented in the AC Characteristics section of this data sheet. If the capacitive load on GPA0 is 70 pF, then a typical rise time is 6.5 ns. From Figure 18, the same load gives a typical fall time of 7 ns. Élan™SC520 Microcontroller Data Sheet 51
