Answers Database
XPLA Architecture: JTAG pins with internal weak pull-up/down resistors.
Record #7593
Product Family: Hardware
Product Line: R5000
Product Part: R5128
Problem Title:
XPLA Architecture: JTAG pins with internal weak pull-up/down resistors.
Problem Description:
Urgency: Hot
General Description: Do the JTAG pins have a weak pull-up/down
resistor when these pins are reserved for this function?
Solution 1:
The weak pull-up/down is not enabled when the JTAG function is
implemented. The I/Os are simply tri-stated and therefore it is advisable
to implement a weak pull-up/down resistor in your design. This will
prevent the JTAG inputs from floating which eliminates the chance that
the CoolRunner would draw higher currents from the power supply.
Please note that the other tristated I/Os, by default, retain their weak
pull-up/down implementation as allowed by that part's features.
End of Record #7593 - Last Modified: 10/11/99 16:34 |
