What is buffer, core?

A temporary storage area, usually in RAM. The purpose of most buffers is to act as a holding area, enabling the CPU to manipulate data before transferring it to a device.

在数据传输中，用来弥补不同数据处理速率速度差距的存储装置叫做缓冲器。把数据存放到缓冲器中的技术叫做缓冲。

A buffer is a data area shared by hardware devices or program processes that operate at different speeds or with different sets of priorities. The buffer allows each device or process to operate without being held up by the other. In order for a buffer to be effective, the size of the buffer and the algorithms for moving data into and out of the buffer need to be considered by the buffer designer. Like a cache, a buffer is a "midpoint holding place" but exists not so much to accelerate the speed of an activity as to support the coordination of separate activities.

This term is used both in programming and in hardware. In programming, buffering sometimes implies the need to screen data from its final intended place so that it can be edited or otherwise processed before being moved to a regular file or database.

CONTRIBUTORS:

Janis Small

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• Core: In digital electronics, it typically refers to a relatively large, general-purpose logic function that is used as a building block in a chip design. Examples are microprocessor, microcontroller and DSP cores. Cores may be developed internally, but are generally purchased from third-party intellectual property (IP) vendors.
• Soft Core: A block of digital logic that is designed to be implemented in an ASIC or FPGA chip. A soft core is typically delivered in RTL, which is a hardware description language that defines logic at a higher level than a "hard core," which is at the gate level. A chip design may comprises one or more soft cores combined with one or more hard cores along with other blocks of user-defined logic. Occasionally, soft cores are delivered as gate-level netlists or schematics rather than RTL.
• Soft Cores in ASICs
  For ASIC chips, the RTL soft core and other RTL associated with the design are synthesized into a gate-level netlist. Based on the netlist, the logic gates are placed and routed and then turned into photomasks to make the chip. The ultimate realization of the soft core is hardwired logic gates formed of transistors and their interconnections.
• Soft Cores in FPGAs
  With FPGAs, the resulting netlist is used to generate a configuration file that will be used to program the lookup tables and configurable logic blocks inside the device.
  
  
• Hard Core: A block of digital logic that is designed to be implemented in an ASIC or FPGA chip. A chip design may be made up of one or more hard cores combined with one or more soft cores along with other blocks of user-defined logic.
  
  For ASIC chips, a hard core is delivered as logic gates in which their physical locations relative to each other and their interconnections are predefined. This block will be treated as a "black box" by the place-and-route software that processes the entire design. The location of the block as a whole may be determined by the software, but the block's internal contents are "locked down."
  
  With FPGAs, hard cores are already physically implemented as hardwired blocks embedded into the FPGA's fabric.
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  How Hard Cores Fit In
  

  When used in an ASIC chip, information about the hard core is entered at various stages to make room for it before its actual layers are added. With FPGAs, floor planning is still done, but the microprocessor core and other IP blocks are already in place. Consequently, instead of a gate-level netlist, a lookup table/configurable logic block (LUT/CLB) netlist is created, and the final output for FPGAs is a configuration file rather than GDSII files.
• Die: An unpackaged, bare chip. A die is the formal term for the square of silicon containing an integrated circuit. Die is singular, and dice is plural. The terms die and chip are often used synonymously.
  
  
  
  Dice on a Wafer
  

  This picture of several dice on the wafer shows the various subsystems on each die (chip). This image is called a "beauty shot," because the different areas are colored for presentation. (Image courtesy of Texas Instruments, Inc.)