litex/top.py

79 lines
1.9 KiB
Python

from fractions import Fraction
from migen.fhdl.structure import *
from migen.fhdl import verilog, autofragment
from migen.bus import wishbone, asmibus, wishbone2asmi, csr, wishbone2csr
from milkymist import m1crg, lm32, norflash, uart, sram#, s6ddrphy
import constraints
MHz = 1000000
clk_freq = (83 + Fraction(1, 3))*MHz
sram_size = 4096 # in bytes
l2_size = 8192 # in bytes
def get():
#
# ASMI
#
#ddrphy0 = s6ddrphy.S6DDRPHY(13, 2, 128)
asmihub0 = asmibus.Hub(23, 128, 12) # TODO: get hub from memory controller
asmiport_wb = asmihub0.get_port()
asmihub0.finalize()
#
# WISHBONE
#
cpu0 = lm32.LM32()
norflash0 = norflash.NorFlash(25, 12)
sram0 = sram.SRAM(sram_size//4)
wishbone2asmi0 = wishbone2asmi.WB2ASMI(l2_size//4, asmiport_wb)
wishbone2csr0 = wishbone2csr.WB2CSR()
# norflash 0x00000000 (shadow @0x80000000)
# SRAM/debug 0x10000000 (shadow @0x90000000)
# USB 0x20000000 (shadow @0xa0000000)
# Ethernet 0x30000000 (shadow @0xb0000000)
# SDRAM 0x40000000 (shadow @0xc0000000)
# CSR bridge 0x60000000 (shadow @0xe0000000)
wishbonecon0 = wishbone.InterconnectShared(
[
cpu0.ibus,
cpu0.dbus
], [
(binc("000"), norflash0.bus),
(binc("001"), sram0.bus),
(binc("10"), wishbone2asmi0.wishbone),
(binc("11"), wishbone2csr0.wishbone)
],
register=True,
offset=1)
#
# CSR
#
uart0 = uart.UART(0, clk_freq, baud=115200)
csrcon0 = csr.Interconnect(wishbone2csr0.csr, [uart0.bank.interface])
#
# Interrupts
#
interrupts = Fragment([
cpu0.interrupt[0].eq(uart0.events.irq)
])
#
# Housekeeping
#
crg0 = m1crg.M1CRG(50*MHz, clk_freq)
frag = autofragment.from_local() + interrupts
src_verilog, vns = verilog.convert(frag,
{crg0.trigger_reset},
name="soc",
clk_signal=crg0.sys_clk,
rst_signal=crg0.sys_rst,
return_ns=True)
src_ucf = constraints.get(vns, crg0, norflash0, uart0)
return (src_verilog, src_ucf)