Z-World RabbitCore RCM3200, Руководство пользователя

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32 RabbitCore RCM3200
A.4 I/O Buffer Sourcing and Sinking Limit
Unless otherwise specified, the Rabbit I/O buffers are capable of sourcing and sinking
6.8 mA of current per pin at full AC switching speed. Full AC switching assumes a
29.4 MHz CPU clock and capacitive loading on address and data lines of less than 70 pF
per pin. The absolute maximum operating voltage on all I/O is 5.5 V.
Table A-6 shows the AC and DC output drive limits of the parallel I/O buffers when the
Rabbit 3000 is used in the RCM3200.
Under certain conditions, the maximum instantaneous AC/DC sourcing or sinking current
may 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 does
not exceed three per V
DD
or V
SS
pad, or up to six outputs between pads. Similarly, the
maximum 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 V
DD
or V
SS
pad, or up to six outputs
between pads. The V
DD
bus can handle up to 35 mA, and the V
SS
bus can handle up to
28 mA. All these analyses were measured at 100°C.
Table A-6. I/O Buffer Sourcing and Sinking Capability
Pin Name
Output Drive (Full AC Switching)
Sourcing/Sinking Limits
(mA)
Sourcing Sinking
All data, address, and I/O
lines with clock doubler
enabled
6.8 6.8