668-0003-C Rabbit Semiconductor, 668-0003-C Datasheet - Page 70

• Manufacturer Part Number: 668-0003-C
• Description: IC CPU RABBIT2000 30MHZ 100PQFP
• Manufacturer: Rabbit Semiconductor

Specifications of 668-0003-C

• Rohs Status: RoHS non-compliant
• Processor Type: Rabbit 2000 8-Bit
• Speed: 30MHz
• Voltage: 2.7V, 3V, 3.3V, 5V
• Mounting Type: Surface Mount
• Package / Case: 100-MQFP, 100-PQFP
• Features: -
• Other names: 316-1004; 668-0003

5.7 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 switching assumes 22.11 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.
Table 5-6 shows the AC and DC output drive limits of the parallel I/O buffers.
64
* The maximum DC sourcing current for I/O buffers between V
† The maximum DC sinking current for I/O buffers between V
‡ The maximum DC output drive on I/O buffers must be adjusted to take
**The combined sourcing from Port D [7:0] may need to be adjusted so
Output Port Name
PA [7:0]
PB [7:6]
PC [6, 4, 2, 0]
PD [7:4]
PD [3:0]
PE [7:0]
is 112 mA.
150 mA.
into consideration the current demands made my AC switching out-
puts, capacitive loading on switching outputs, and switching voltage.
The current ascribed to AC switching is the average current that flows
while AC switching is taking place. This can be computed using I =
CVf, where f is the number of transitions per second, C is the capaci-
tance switched, and V is the voltage swing. For example, if 12,000,000
transitions per second take place with a 5 V swing driving 100 pF, then
I = 6 mA for one pin. The current attributable to all the pins between
the power or ground pins must be summed to test the limits, including
the current attributable to switching current or DC current.
The current drawn by all switching and non-switching I/O must not
exceed the limits specified in the first two footnotes.
as not to exceed the 112 mA sourcing limit requirement specified
above.
Table 5-6. I/O Buffer Sourcing and Sinking Capability
Pin Name
**
Full AC Switching
SRC/SNK
8/8
8/8
8/8
8/8
16/16
8/8
Sourcing
Output Drive
Rabbit 2000 Microprocessor User’s Manual
*
/Sinking
(mA)
Maximum
Drive
SRC/SNK
12/12
12/12
12/12
12/12
25/25
12/12
†
Limits
‡
DC Output
SS
DD
pins is
pins