XC3000 | XC4000E | XC4000X | XC5200 | XC9000 | Spartan | SpartanXL | Spartan2 | Virtex |
---|---|---|---|---|---|---|---|---|
N/A | Primitive | Primitive | N/A | N/A | N/A | N/A | N/A | N/A |
WOR2AND is a 2-input (I1 and I2) OR gate/buffer with an open-drain output (O). It is used in bus applications by tying multiple open-drain outputs together. When both inputs (I1 and I2) are Low, the output (O) is Low. When either input is High, the output is off; WOR2AND cannot source or sink current. To establish an output High level, tie a pull-up resistor(s) to the output (O). One pull-up resistor uses the least power, two pull-up resistors achieve the fastest Low-to-High speed.
To indicate two pull-up resistors, append 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.