yosys/techlibs/xilinx/brams.txt

# This is a very simplified description of the capabilities of
# the Xilinx RAMB36 core. But it is a start..
#
bram XILINX_RAMB36_SDP32
  init 1
  abits 10
  dbits 32
  groups 2
  ports  1 1
  wrmode 1 0
  enable 4 0
  transp 0 2
  clocks 1 2
endbram

match XILINX_RAMB36_SDP32
  min bits 1024
endmatch