I/O Buffer Sourcing And Sinking Limit - Rabbit RabbitCore RCM3400 User Manual

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-8 shows the AC and DC output drive limits of the parallel I/O buffers when the
Rabbit 3000 is used in the RCM3400.
Table A-8. I/O Buffer Sourcing and Sinking Capability
Pin Name
All data, address, and I/O
lines with clock doubler
enabled
Under certain conditions, the maximum instantaneous AC/DC sourcing or sinking current
may be greater than the limits outlined in Table A-8. 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
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
between pads. The V
28 mA. All these analyses were measured at 100°C.
User's Manual
Output Drive (Full AC Switching)
or V pad, or up to six outputs between pads. Similarly, the
DD SS
bus can handle up to 35 mA, and the V
DD
Sourcing/Sinking Limits
(mA)
Sourcing
6.8
or V pad, or up to six outputs
DD SS
Sinking
6.8
bus can handle up to
SS
67