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WAND1, 4, 8, 16

Open-Drain Buffers

Element
XC3000
XC4000E
XC4000X
XC5200
XC9000
Spartan
SpartanXL
Virtex
WAND1
N/A
Primitive
Primitive
N/A
N/A
N/A
N/A
N/A
WAND4,
WAND8.
WAND16
N/A
Macro
Macro
N/A
N/A
N/A
N/A
N/A

figures/x3905n.gif

figures/x3915n.gif

figures/x3916n.gif

figures/x3917n.gif

WAND1, WAND4, WAND8, and WAND16 are single and multiple open-drain buffers. Each buffer has an input (I) and an open-drain output (O). When any of the inputs is Low, the output is Low. When all the inputs are High, the output is off. To obtain a High output, add pull-up resistors to the output (O). One pull-up resistor uses the least power, and two pull-up resistors achieve the fastest Low-to-High transition.

To indicate two pull-up resistors, add a DOUBLE parameter to the pull-up symbol attached to the output (O) node. Refer to the appropriate CAE tool interface user guide for details.

Figure 10.11 WAND8 Implementation XC4000

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