Filter
Top Products
Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors—General Hardware
Design Considerations
Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
HDD February 2007
36 Document Number: 305261; Revision: 004
3.6.1 Signal Interface
3.6.2 Design Notes
The drive strength for GPIO[15:14] is limited to 8 mA, while GPIO [13:0] can output up
to 16 mA. When used for driving high current devices such as LEDs or relays, make
sure to place current-limiting resistor or permanent damage to the IXP45X/IXP46X
network processors driver might be done.
It is recommended that a 10-KΩ pull-up resistor be used when a GPIO port is
configured as an input and not being used.
Table 13. GPIO Signal Recommendations
Name
Input/
Output
Pull
Up/
Down
Recommendations
GPIO[12:0] I/O Yes
General Purpose Input/Output.
If used as an input interrupt, should be pull-up or pull-down, depending on the level of
activation. For example:
Active high, use a 10-KΩ pull-down resistor.
Active low, use a 10-KΩ pull-up resistor.
Should be pulled high through a 10-KΩ resistor when not used.
GPIO[13] I/O Yes
General Purpose Input/Output.
Same recommendations as GPIO[12:0]
GPIO[14] I/O Yes
General Purpose Input/Output.
Same recommendations as GPIO[12:0]. An additional feature includes Clock generation, max
clock out 33.33 MHz., set as input by default.
GPIO[15] I/O Yes
General Purpose Input/Output.
Same recommendations as GPIO[12:0]. An additional feature includes Clock generation, max
clock out 33.33 MHz., set as output by default.