litex/top.py

125 lines
2.8 KiB
Python

from fractions import Fraction
from math import ceil
from migen.fhdl.structure import *
from migen.fhdl import verilog, autofragment
from migen.bus import wishbone, wishbone2asmi, csr, wishbone2csr, dfi
from milkymist import m1crg, lm32, norflash, uart, sram, s6ddrphy, dfii, asmicon
import constraints
MHz = 1000000
clk_freq = (83 + Fraction(1, 3))*MHz
sram_size = 4096 # in bytes
l2_size = 8192 # in bytes
clk_period_ns = 1000000000/clk_freq
def ns(t, margin=True):
if margin:
t += clk_period_ns/2
return ceil(t/clk_period_ns)
sdram_phy = asmicon.PhySettings(
dfi_d=64,
nphases=2,
rdphase=0,
wrphase=1
)
sdram_geom = asmicon.GeomSettings(
bank_a=2,
row_a=13,
col_a=10
)
sdram_timing = asmicon.TimingSettings(
tRP=ns(15),
tRCD=ns(15),
tREFI=ns(7800, False),
tRFC=ns(70)
)
def ddrphy_clocking(crg, phy):
names = [
"clk2x_270",
"clk4x_wr",
"clk4x_wr_strb",
"clk4x_rd",
"clk4x_rd_strb"
]
comb = [getattr(phy, name).eq(getattr(crg, name)) for name in names]
return Fragment(comb)
def get():
#
# ASMI
#
asmicon0 = asmicon.ASMIcon(sdram_phy, sdram_geom, sdram_timing, 16)
asmiport_wb = asmicon0.hub.get_port()
asmicon0.finalize()
#
# DFI
#
ddrphy0 = s6ddrphy.S6DDRPHY(sdram_geom.mux_a, sdram_geom.bank_a, sdram_phy.dfi_d)
dfii0 = dfii.DFIInjector(1, sdram_geom.mux_a, sdram_geom.bank_a, sdram_phy.dfi_d, sdram_phy.nphases)
dficon0 = dfi.Interconnect(dfii0.master, ddrphy0.dfi)
dficon1 = dfi.Interconnect(asmicon0.dfi, dfii0.slave)
#
# 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,
dfii0.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 + ddrphy_clocking(crg0, ddrphy0)
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, ddrphy0)
return (src_verilog, src_ucf)