milkymist/minimac3/__init__.py

   1 from migen.fhdl.structure import *
   2 from migen.bank.description import *
   3 from migen.bank.eventmanager import *
   4 from migen.bank import csrgen
   5 from migen.bus import wishbone
   6
   7 _count_width = 11
   8
   9 class MiniMAC:
  10         def __init__(self, address):
  11                 # PHY signals
  12                 self.phy_tx_clk = Signal()
  13                 self.phy_tx_data = Signal(BV(4))
  14                 self.phy_tx_en = Signal()
  15                 self.phy_tx_er = Signal()
  16                 self.phy_rx_clk = Signal()
  17                 self.phy_rx_data = Signal(BV(4))
  18                 self.phy_dv = Signal()
  19                 self.phy_rx_er = Signal()
  20                 self.phy_col = Signal()
  21                 self.phy_crs = Signal()
  22                 self.phy_rst_n = Signal()
  23
  24                 # CPU interface
  25                 self._phy_reset = RegisterField("phy_reset", reset=1)
  26                 self._rx_count_0 = RegisterField("rx_count_0", _count_width, access_bus=READ_ONLY, access_dev=WRITE_ONLY)
  27                 self._rx_count_1 = RegisterField("rx_count_1", _count_width, access_bus=READ_ONLY, access_dev=WRITE_ONLY)
  28                 self._tx_count = RegisterField("tx_count", _count_width, access_dev=READ_WRITE)
  29                 self._tx_start = RegisterField("tx_start", access_bus=WRITE_ONLY)
  30                 regs = [self._phy_reset, self._rx_count_0, self._rx_count_1, self._tx_count, self._tx_start]
  31
  32                 self._rx_event_0 = EventSourcePulse()
  33                 self._rx_event_1 = EventSourcePulse()
  34                 self._tx_event = EventSourcePulse()
  35                 self.events = EventManager(self._rx_event_0, self._rx_event_1, self._tx_event)
  36
  37                 self.bank = csrgen.Bank(regs + self.events.get_registers(), address=address)
  38                 self.membus = wishbone.Interface()
  39
  40         def get_fragment(self):
  41                 init = Signal(reset=1)
  42                 rx_ready_0 = Signal()
  43                 rx_ready_1 = Signal()
  44                 rx_pending_0 = self._rx_event_0.pending
  45                 rx_pending_1 = self._rx_event_1.pending
  46                 rx_pending_0_r = Signal()
  47                 rx_pending_1_r = Signal()
  48                 comb = [
  49                         self.phy_rst_n.eq(~self._phy_reset.field.r),
  50
  51                         rx_ready_0.eq(init | (rx_pending_0_r & ~rx_pending_0)),
  52                         rx_ready_1.eq(init | (rx_pending_1_r & ~rx_pending_1)),
  53
  54                         self._tx_count.field.w.eq(0),
  55                         self._tx_count.field.we.eq(self._tx_event.trigger)
  56                 ]
  57                 sync = [
  58                         init.eq(0),
  59                         rx_pending_0_r.eq(rx_pending_0),
  60                         rx_pending_1_r.eq(rx_pending_1)
  61                 ]
  62                 inst = [
  63                         Instance("minimac3",
  64                                 [
  65                                         ("rx_done_0", self._rx_event_0.trigger),
  66                                         ("rx_count_0", self._rx_count_0.field.w),
  67                                         ("rx_done_1", self._rx_event_1.trigger),
  68                                         ("rx_count_1", self._rx_count_1.field.w),
  69
  70                                         ("tx_done", self._tx_event.trigger),
  71
  72                                         ("wb_dat_o", self.membus.dat_r),
  73                                         ("wb_ack_o", self.membus.ack),
  74
  75                                         ("phy_tx_data", self.phy_tx_data),
  76                                         ("phy_tx_en", self.phy_tx_en),
  77                                         ("phy_tx_er", self.phy_tx_er),
  78                                 ], [
  79                                         ("rx_ready_0", rx_ready_0),
  80                                         ("rx_ready_1", rx_ready_1),
  81
  82                                         ("tx_start", self._tx_start.re),
  83                                         ("tx_count", self._tx_count.field.r),
  84
  85                                         ("wb_adr_i", self.membus.adr),
  86                                         ("wb_dat_i", self.membus.dat_w),
  87                                         ("wb_sel_i", self.membus.sel),
  88                                         ("wb_stb_i", self.membus.stb),
  89                                         ("wb_cyc_i", self.membus.cyc),
  90                                         ("wb_we_i", self.membus.we),
  91
  92                                         ("phy_tx_clk", self.phy_tx_clk),
  93                                         ("phy_rx_clk", self.phy_rx_clk),
  94                                         ("phy_rx_data", self.phy_rx_data),
  95                                         ("phy_dv", self.phy_dv),
  96                                         ("phy_rx_er", self.phy_rx_er),
  97                                         ("phy_col", self.phy_col),
  98                                         ("phy_crs", self.phy_crs)
  99                                 ],
 100                                 clkport="sys_clk",
 101                                 rstport="sys_rst"
 102                         )
 103                 ]
 104                 return Fragment(comb, sync, instances=inst) \
 105                         + self.events.get_fragment() \
 106                         + self.bank.get_fragment()