58 RabbitCore RCM3000A.4 I/O Buffer Sourcing and Sinking LimitUnless otherwise specified, the Rabbit 3000 I/O buffers are capable of sourcing and sink-ing 6.8 mA of current per pin at full AC switching speed. Full AC switching assumes a29.4 MHz CPU clock and capacitive loading on address and data lines of less than 70 pFper pin. The maximum Vcc is 3.6 V, and the absolute maximum operating voltage on allparallel I/O is 5.5 V.Table A-6 shows the AC and DC output drive limits of the parallel I/O buffers when theRabbit 3000 is used in the RCM3000.Under certain conditions, the maximum instantaneous AC/DC sourcing or sinking currentmay be greater than the limits outlined in Table A-6. The maximum AC/DC sourcing cur-rent can be as high as 12.5 mA per buffer as long as the number of sourcing buffers doesnot exceed three per V DD or V SS pad, or up to six outputs between pads. Similarly, themaximum AC/DC sinking current can be as high as 8.5 mA per buffer as long as the num-ber of sinking buffers does not exceed three per VDD or VSS pad, or up to six outputsbetween pads. The V DD bus can handle up to 35 mA, and the V SS bus can handle up to28 mA. All these analyses were measured at 100°C.Table A-6. I/O Buffer Sourcing and Sinking CapabilityPin NameOutput Drive (Full AC Switching)Sourcing/Sinking Limits(mA)Sourcing SinkingAll data, address, and I/Olines with clock doublerenabled6.8 6.8Downloaded from Elcodis.com electronic components distributor
