OpenFPGA/openfpga_flow/vpr_arch/README.md

Naming convention for VPR architecture files

Please reveal the following architecture features in the names to help quickly spot architecture files.

• k<lut_size>_: Look-Up Table (LUT) size of FPGA. If you have fracturable LUTs or multiple LUT circuits, this should be largest input size.
  • The keyword 'frac' is to specify if fracturable LUT is used or not.
  • The keyword 'Native' is to specify if fracturable LUT design is a native one (without mode switch) or a standard one (with mode switch).
• N<le_size>: Number of logic elements for a CLB. If you have multiple CLB architectures, this should be largest number.
• tileable: If the routing architecture is tileable or not.
  • The keyword 'IO' specifies if the I/O tile is tileable or not
• adder_chain: If hard adder/carry chain is used inside CLBs
• register_chain: If shift register chain is used inside CLBs
• scan_chain: If scan chain testing infrastructure is used inside CLBs
• __mem<mem_size>: If block RAM (BRAM) is used or not. If used, the memory size should be clarified here. The keyword 'wide' is to specify if the BRAM spans more than 1 column. The keyword 'frac' is to specify if the BRAM is fracturable to operate in different modes.
• __dsp<dsp_size>: If Digital Signal Processor (DSP) is used or not. If used, the input size should be clarified here. The keyword 'wide' is to specify if the DSP spans more than 1 column. The keyword 'frac' is to specify if the DSP is fracturable to operate in different modes.
• aib: If the Advanced Interface Bus (AIB) is used in place of some I/Os.
• multi_io_capacity: If I/O capacity is different on each side of FPGAs.
• reduced_io: If I/Os only appear a certain or multiple sides of FPGAs
• <feature_size>: The technology node which the delay numbers are extracted from.
• TileOrgz: How tile is organized.
  • Top-left (Tl): the pins of a tile are placed on the top side and left side only
  • Top-right (Tr): the pins of a tile are placed on the top side and right side only
  • Bottom-right (Br): the pins of a tile are placed on the bottom side and right side only

Other features are used in naming should be listed here.