constraints.py

   1 def get(ns, reset0, norflash0, uart0):
   2         constraints = []
   3         def add(signal, pin, vec=-1, iostandard="LVCMOS33", extra=""):
   4                 constraints.append((ns.get_name(signal), vec, pin, iostandard, extra))
   5         def add_vec(signal, pins, iostandard="LVCMOS33", extra=""):
   6                 i = 0
   7                 for p in pins:
   8                         add(signal, p, i, iostandard, extra)
   9                         i += 1
  10
  11         add(reset0.trigger_reset, "AA4")
  12         add(reset0.ac97_rst_n, "D6")
  13         add(reset0.videoin_rst_n, "W17")
  14         add(reset0.flash_rst_n, "P22", extra="SLEW = FAST | DRIVE = 8")
  15
  16         add_vec(norflash0.adr, ["L22", "L20", "K22", "K21", "J19", "H20", "F22",
  17                 "F21", "K17", "J17", "E22", "E20", "H18", "H19", "F20",
  18                 "G19", "C22", "C20", "D22", "D21", "F19", "F18", "D20", "D19"],
  19                 extra="SLEW = FAST | DRIVE = 8")
  20         add_vec(norflash0.d, ["AA20", "U14", "U13", "AA6", "AB6", "W4", "Y4", "Y7",
  21                 "AA2", "AB2", "V15", "AA18", "AB18", "Y13", "AA12", "AB12"],
  22                 extra = "SLEW = FAST | DRIVE = 8 | PULLDOWN")
  23         add(norflash0.oe_n, "M22", extra="SLEW = FAST | DRIVE = 8")
  24         add(norflash0.we_n, "N20", extra="SLEW = FAST | DRIVE = 8")
  25         add(norflash0.ce_n, "M21", extra="SLEW = FAST | DRIVE = 8")
  26
  27         add(uart0.tx, "L17", extra="SLEW = SLOW")
  28         add(uart0.rx, "K18", extra="PULLUP")
  29
  30         r = ""
  31         for c in constraints:
  32                 r += "NET \"" + c[0]
  33                 if c[1] >= 0:
  34                         r += "(" + str(c[1]) + ")"
  35                 r += "\" LOC = " + c[2]
  36                 r += " | IOSTANDARD = " + c[3]
  37                 if c[4]:
  38                         r += " | " + c[4]
  39                 r += ";\n"
  40
  41         r += """
  42 NET "sys_clk" LOC = AB11 | IOSTANDARD = LVCMOS33;
  43 NET "sys_clk" TNM_NET = "GRPclk50";
  44 TIMESPEC "TSclk50" = PERIOD "GRPclk50" 20 ns HIGH 50%;
  45         """
  46
  47         return r