RabbitCore RCM2200, User Manual

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A– 8 RabbitCore RCM2200 Specifications RabbitCore RCM2200
A.4 I/O Buffer Sourcing and
Sinking Limit
Unless otherwise specified, the Rabbit I/O buffers
are capable of sourcing and sinking 8 mA of current
per pin at full AC switching speed. Full AC switch-
ing assumes a 25.8 MHz CPU clock and capacitive
loading on address and data lines of less than 100 pF
per pin. Address pin A0 and data pin D0 are rated at
16 mA each. Pins A1–A12 and D1–D7 are each
rated at 8 mA. The absolute maximum operating
voltage on all I/O is V
DD
+ 0.5 V, or 5.5 V.
Table A–6 shows the AC and DC output drive lim-
its of the parallel I/O buffers when the Rabbit 2000
is used in the RabbitCore RCM2200.
Table A–6: I/O Buffer Sourcing and Sinking Capability
Pin Name
Output Drive
Sourcing
*
/Sinking
†
Limits
(mA)
Output Port Name
Full AC Switching
SRC/SNK
Maximum
‡
DC
Output Drive
SRC/SNK
PA [7:0] 8/8 12/12
PB [7, 1, 0] 8/8 12/12
PC [6, 2, 0] 8/8 12/12
PD [5::4] 8/8 12/12
PD3
**
16/16 25/25
PE [7, 5, 4, 1, 0] 8/8 12/12
* The maximum DC sourcing current for I/O buffers between V
DD
pins is 112 mA.
† The maximum DC sinking current for I/O buffers between V
SS
pins
is 150 mA.
‡ The maximum DC output drive on I/O buffers must be adjusted to
take into consideration the current demands made my AC switching
outputs, capacitive loading on switching outputs, and switching volt-
age.
The current drawn by all switching and nonswitching I/O must not
exceed the limits specified in the first two footnotes.
** The combined sourcing from Port D [7:0] may need to be adjusted so
as not to exceed the 112 mA sourcing limit requirement specified in
the first footnote.