Merge pull request #161 from enjoy-digital/wishbone_tx_rx_buses

mac/wishbone/LiteEthMACWishboneInterface: Expose separate TX/RX Wishb…

liteeth/gen.py

@@ -3,7 +3,7 @@
 #
 # This file is part of LiteEth.
 #
-# Copyright (c) 2015-2023 Florent Kermarrec <florent@enjoy-digital.fr>
+# Copyright (c) 2015-2024 Florent Kermarrec <florent@enjoy-digital.fr>
 # Copyright (c) 2020 Xiretza <xiretza@xiretza.xyz>
 # Copyright (c) 2020 Stefan Schrijvers <ximin@ximinity.net>
 # Copyright (c) 2022 Victor Suarez Rovere <suarezvictor@gmail.com>
@@ -413,13 +413,32 @@ class MACCore(PHYCore):
           # AXI-Lite Interface -----------------------------------------------------------------------
           axil_bus = axi.AXILiteInterface(address_width=32, data_width=32)
           platform.add_extension(axil_bus.get_ios("bus"))
-          self.submodules += axi.Wishbone2AXILite(ethmac.bus, axil_bus)
           self.comb += axil_bus.connect_to_pads(self.platform.request("bus"), mode="slave")
           self.bus.add_master(master=axil_bus)
 
-        ethmac_region_size = (nrxslots + ntxslots)*buffer_depth
+        ethmac_rx_region_size = ethmac.rx_slots.constant*ethmac.slot_size.constant
-        ethmac_region = SoCRegion(origin=self.mem_map.get("ethmac", None), size=ethmac_region_size, cached=False)
+        ethmac_tx_region_size = ethmac.tx_slots.constant*ethmac.slot_size.constant
-        self.bus.add_slave(name="ethmac", slave=ethmac.bus, region=ethmac_region)
+        ethmac_region_size    = ethmac_rx_region_size + ethmac_tx_region_size
+        self.bus.add_region("ethmac", SoCRegion(
+            origin = self.mem_map.get("ethmac", None),
+            size   = ethmac_region_size,
+            linker = True,
+            cached = False,
+        ))
+        ethmac_rx_region = SoCRegion(
+            origin = self.bus.regions["ethmac"].origin + 0,
+            size   = ethmac_rx_region_size,
+            linker = True,
+            cached = False,
+        )
+        self.bus.add_slave(name="ethmac_rx", slave=ethmac.bus_rx, region=ethmac_rx_region)
+        ethmac_tx_region = SoCRegion(
+            origin = self.bus.regions["ethmac"].origin + ethmac_rx_region_size,
+            size   = ethmac_tx_region_size,
+            linker = True,
+            cached = False,
+        )
+        self.bus.add_slave(name="ethmac_tx", slave=ethmac.bus_tx, region=ethmac_tx_region)
 
         # Interrupt Interface ----------------------------------------------------------------------
         self.comb += self.platform.request("interrupt").eq(self.ethmac.ev.irq)

liteeth/mac/__init__.py

@@ -77,7 +77,7 @@ class LiteEthMAC(Module, AutoCSR):
             if full_memory_we:
                 wishbone_interface = FullMemoryWE()(wishbone_interface)
             self.submodules.interface = wishbone_interface
-            self.ev, self.bus = self.interface.sram.ev, self.interface.bus
+            self.ev, self.bus_rx, self.bus_tx = self.interface.sram.ev, self.interface.bus_rx, self.interface.bus_tx
             self.csrs = self.interface.get_csrs() + self.core.get_csrs()
             if interface == "hybrid":
                 # Hardware MAC

liteeth/mac/wishbone.py

@@ -1,13 +1,15 @@
 #
 # This file is part of LiteEth.
 #
-# Copyright (c) 2015-2021 Florent Kermarrec <florent@enjoy-digital.fr>
+# Copyright (c) 2015-2024 Florent Kermarrec <florent@enjoy-digital.fr>
 # Copyright (c) 2015-2016 Sebastien Bourdeauducq <sb@m-labs.hk>
 # Copyright (c) 2021 Leon Schuermann <leon@is.currently.online>
 # SPDX-License-Identifier: BSD-2-Clause
 
 import math
 
+from litex.gen import *
+
 from liteeth.common import *
 from liteeth.mac import sram
 
@@ -15,53 +17,66 @@ from litex.soc.interconnect import wishbone
 
 # MAC Wishbone Interface ---------------------------------------------------------------------------
 
-class LiteEthMACWishboneInterface(Module, AutoCSR):
+class LiteEthMACWishboneInterface(LiteXModule):
     def __init__(self, dw, nrxslots=2, ntxslots=2, endianness="big", timestamp=None,
         rxslots_read_only  = True,
         txslots_write_only = False,
     ):
         self.sink   = stream.Endpoint(eth_phy_description(dw))
         self.source = stream.Endpoint(eth_phy_description(dw))
-        self.bus    = wishbone.Interface(data_width=dw)
+        self.bus_rx = wishbone.Interface(data_width=dw)
+        self.bus_tx = wishbone.Interface(data_width=dw)
 
         # # #
 
         # Storage in SRAM.
+        # ----------------
         sram_depth = math.ceil(eth_mtu/(dw//8))
-        self.submodules.sram = sram.LiteEthMACSRAM(dw, sram_depth, nrxslots, ntxslots, endianness, timestamp)
+        self.sram = sram.LiteEthMACSRAM(dw, sram_depth, nrxslots, ntxslots, endianness, timestamp)
-        self.comb += self.sink.connect(self.sram.sink)
+        self.comb += [
-        self.comb += self.sram.source.connect(self.source)
+            self.sink.connect(self.sram.sink),
+            self.sram.source.connect(self.source),
+        ]
 
-        # Wishbone SRAM interfaces for the writer SRAM (i.e. Ethernet RX).
+        # Ethernet Wishbone SRAM interfaces exposure.
-        wb_rx_sram_ifs = []
+        # -------------------------------------------
-        for n in range(nrxslots):
+        self._expose_wishbone_sram_interfaces(
-            wb_rx_sram_ifs.append(wishbone.SRAM(
+            bus        = self.bus_rx,
-                mem_or_size = self.sram.writer.mems[n],
+            dw         = dw,
-                read_only   = rxslots_read_only,
+            mems       = self.sram.writer.mems,
-                bus         = wishbone.Interface(data_width = dw)
+            nslots     = nrxslots,
+            read_only  = rxslots_read_only,
+            write_only = False,
+        )
+        self._expose_wishbone_sram_interfaces(
+            bus        = self.bus_tx,
+            dw         = dw,
+            mems       = self.sram.reader.mems,
+            nslots     = ntxslots,
+            read_only  = False,
+            write_only = txslots_write_only,
+        )
+
+    def _expose_wishbone_sram_interfaces(self, bus, dw, mems, nslots, read_only, write_only):
+        # SRAMs.
+        wb_sram_ifs = []
+        for n in range(nslots):
+            wb_sram_ifs.append(wishbone.SRAM(
+                mem_or_size = mems[n],
+                read_only   = read_only,
+                write_only  = write_only,
+                bus         = wishbone.Interface(data_width=dw)
             ))
 
-        # Wishbone SRAM interfaces for the reader SRAM (i.e. Ethernet TX).
+        # Expose SRAMs on Bus.
-        wb_tx_sram_ifs = []
-        for n in range(ntxslots):
-            wb_tx_sram_ifs.append(wishbone.SRAM(
-                mem_or_size = self.sram.reader.mems[n],
-                write_only  = txslots_write_only,
-                bus         = wishbone.Interface(data_width = dw)
-            ))
-
-        # Expose Wishbone SRAMs on a single Wishbone bus.
-        # CHECKME: Check Decoder width for 64-bit.
         wb_slaves      = []
+        sram_depth     = math.ceil(eth_mtu/(dw//8))
         decoderoffset  = log2_int(sram_depth, need_pow2=False)
-        rx_decoderbits = log2_int(len(wb_rx_sram_ifs))
+        decoderbits    = log2_int(len(wb_sram_ifs))
-        tx_decoderbits = log2_int(len(wb_tx_sram_ifs))
-        decoderbits    = max(rx_decoderbits, tx_decoderbits) + 1
-        wb_sram_ifs    = wb_rx_sram_ifs + wb_tx_sram_ifs
         for n, wb_sram_if in enumerate(wb_sram_ifs):
             def slave_filter(a, v=n):
                 return a[decoderoffset:decoderoffset+decoderbits] == v
             wb_slaves.append((slave_filter, wb_sram_if.bus))
             self.submodules += wb_sram_if
-        wb_con = wishbone.Decoder(self.bus, wb_slaves, register=True)
+        wb_con = wishbone.Decoder(bus, wb_slaves, register=True)
         self.submodules += wb_con

test/test_mac_wishbone.py

@@ -102,12 +102,13 @@ class DUT(Module):
 
 
 def main_generator(dut):
-    wishbone_master = WishboneMaster(dut.ethmac.bus)
+    wishbone_tx_master = WishboneMaster(dut.ethmac.bus_tx)
+    wishbone_rx_master = WishboneMaster(dut.ethmac.bus_rx)
     sram_reader_driver = SRAMReaderDriver(dut.ethmac.interface.sram.reader)
     sram_writer_driver = SRAMWriterDriver(dut.ethmac.interface.sram.writer)
 
     sram_writer_slots_offset = [0x000, 0x200]
-    sram_reader_slots_offset = [0x400, 0x600]
+    sram_reader_slots_offset = [0x000, 0x200]
 
     length = 150+2
 
@@ -121,7 +122,7 @@ def main_generator(dut):
             # fill tx memory
             for i in range(length//4+1):
                 dat = int.from_bytes(tx_payload[4*i:4*(i+1)], "big")
-                yield from wishbone_master.write(sram_reader_slots_offset[slot]+i, dat)
+                yield from wishbone_tx_master.write(sram_reader_slots_offset[slot]+i, dat)
 
             # send tx payload & wait
             yield from sram_reader_driver.start(slot, length)
@@ -135,8 +136,8 @@ def main_generator(dut):
             # get rx payload (loopback on PHY Model)
             rx_payload = []
             for i in range(length//4+1):
-                yield from wishbone_master.read(sram_writer_slots_offset[slot]+i)
+                yield from wishbone_tx_master.read(sram_writer_slots_offset[slot]+i)
-                dat = wishbone_master.dat
+                dat = wishbone_tx_master.dat
                 rx_payload += list(dat.to_bytes(4, byteorder='big'))
 
             # check results