CPLD Schematic Design Guide
A-8
Xilinx Development System
Schematic
Attached to an internal symbol or its output net.
UCF/NCF
INST ABC PWR_MODE=LOW;
Preserving a Node -- KEEP
Applicable Elements
Internal combinational nodes.
Description
Use the logic optimization attributes to control collapsing at specific
points in your design. Logic optimization attributes are normally not
required to process designs.
The KEEP attribute inhibits collapsing of a logic function into any of
its fanouts.
Syntax
KEEP
Schematic
Attach to an internal symbol or its output net.
UCF/NCF
NET ABC KEEP;
Register Preload State -- INIT
Applicable Elements
Registers and registered macros.
Description
The INIT attribute specifies the initialization value to be preloaded
into a register upon power-up. INIT=R specifies a preload value of 0
Summary :
CPLD Schematic Design Guide A-8 Xilinx Development System Schematic Attached to an internal symbol or its output net.
Tags :
keep,net,schematic,logic,internal,ucfncf,applicable,output,symbol,attributes,register,design,init