Link library and Target Library
In Sense Of Synthesis
Synthesis is about converting RTL to gates. The first step in this process is to create an internal netlist, perform technology mapping and later optimize for timing/area/power. Now that the basics are explained
Link library is used for linking the design. If there are some technology cells instantiated in the RTL such as memories, by providing link library the synthesis is able to map it to library cell and understand the interface
Target library is used for technology mapping. All the combo (AND, NAND, NOT, etc) and the sequential (SDFF, DFF, etc) are mapped to equivalent gates from the target library.
In sense of Floorplan, Powerplan, PNR
In IC Compiler (ICC) tool, a "link library" is a library of precompiled object files that are linked with the design during the compilation process. The purpose of a link library is to speed up the design compilation time by providing pre-compiled code for functions and routines that are commonly used in the design.
On the other hand, a "target library" is a collection of physical and timing models that are used to model the behaviour of a specific technology library. Target libraries contain information about the timing, power, and other characteristics of the cells in the technology library. They are used by ICC to optimize the design for the specific technology library being used.
In summary, a link library contains precompiled code that is used during the design compilation process to speed up the process, while a target library contains information about the physical and timing characteristics of the cells in a specific technology library and is used by ICC to optimize the design for that technology library.
Symbols Library :
In IC Compiler (ICC), a symbol library is a collection of pre-built cells or macros that can be used in the design. The cells in a symbol library are typically abstracted versions of physical cells from a target library. These cells have abstracted views that provide information about the functionality of the cell, without specifying the physical details of the cell.
Symbol libraries are important in the design process because they allow designers to quickly access commonly used cells without having to create them from scratch. This can save time and effort, especially for complex designs. Symbol libraries can be customized to include only the cells that are needed for a specific design, making them an efficient way to manage and reuse commonly used cells.
In addition to pre-built cells, a symbol library may also contain abstract views of other design elements, such as I/O pads, power and ground cells, and signal integrity models. These abstract views allow designers to create a complete design without having to specify every detail of every cell.