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STARTUP

User Interface to Global Clock, Reset, and 3-State Controls

XC3000
XC4000E
XC4000X
XC5200
XC9000
Spartan
SpartanXL
Virtex
N/A
Primitive
Primitive
Primitive
N/A
Primitive
Primitive
N/A

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The STARTUP primitive is used for Global Set/Reset, global 3-state control, and the user configuration clock. The Global Set/Reset (GSR) input, when High, sets or resets every flip-flop in the device, depending on the initialization state (S or R) of the flip-flop. Following configuration, the global 3-state control (GTS), when High, forces all the IOB outputs into high impedance mode, which isolates the device outputs from the circuit but leaves the inputs active.

Including the STARTUP symbol in a design is optional. You must include the symbol under the following conditions.

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You can use location constraints to specify the pin from which GSR or GTS (or both) is accessed.

The STARTUP outputs (Q2, Q3, Q1Q4, and DONEIN) display the progress/status of the start-up process following the configuration. Refer to The Programmable Logic Data Book for additional details.

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