litex/top.py

from fractions import Fraction
from math import ceil
from operator import itemgetter

from migen.fhdl.std import *
from migen.bus import wishbone, csr, lasmibus, dfi
from migen.bus import wishbone2lasmi, wishbone2csr
from migen.bank import csrgen
from mibuild.generic_platform import ConstraintError

from milkymist import mxcrg, lm32, norflash, uart, s6ddrphy, dfii, lasmicon, \
	identifier, timer, minimac3, framebuffer, dvisampler, gpio, memtest

version = "2.0"

clk_freq = (83 + Fraction(1, 3))*1000000
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_geom = lasmicon.GeomSettings(
	bank_a=2,
	row_a=13,
	col_a=10
)
sdram_timing = lasmicon.TimingSettings(
	tRP=ns(15),
	tRCD=ns(15),
	tWR=ns(15),
	tWTR=2,
	tREFI=ns(7800, False),
	tRFC=ns(70),

	req_queue_size=8,
	read_time=32,
	write_time=16
)

class MXClockPads:
	def __init__(self, platform):
		self.clk50 = platform.request("clk50")
		self.trigger_reset = 0
		try:
			self.trigger_reset = platform.request("user_btn", 1)
		except ConstraintError:
			pass
		self.norflash_rst_n = platform.request("norflash_rst_n")
		ddram_clock = platform.request("ddram_clock")
		self.ddr_clk_p = ddram_clock.p
		self.ddr_clk_n = ddram_clock.n
		eth_clocks = platform.request("eth_clocks")
		self.eth_phy_clk = eth_clocks.phy
		self.eth_rx_clk = eth_clocks.rx
		self.eth_tx_clk = eth_clocks.tx

class SoC(Module):
	csr_base = 0xe0000000
	csr_map = {
		"crg":					0,
		"uart":					1,
		"dfii":					2,
		"identifier":			3,
		"timer0":				4,
		"minimac":				5,
		"fb":					6,
		"lasmicon":				7,
		"dvisampler0":			8,
		"dvisampler0_edid_mem":	9,
		"dvisampler1":			10,
		"dvisampler1_edid_mem":	11,
		"pots":					12,
		"buttons":				13,
		"leds":					14,
		"memtest_w":			15,
		"memtest_r":			16
	}

	interrupt_map = {
		"uart":			0,
		"timer0":		1,
		"minimac":		2,
		"dvisampler0":	3,
		"dvisampler1":	4,
	}

	def __init__(self, platform, platform_name, with_memtest):
		#
		# DFI
		#
		self.submodules.ddrphy = s6ddrphy.S6DDRPHY(platform.request("ddram"), memtype="DDR", nphases=2, cl=3, bitslip=0)
		self.submodules.dfii = dfii.DFIInjector(sdram_geom.mux_a, sdram_geom.bank_a,
			self.ddrphy.phy_settings.dfi_d, self.ddrphy.phy_settings.nphases)
		self.submodules.dficon0 = dfi.Interconnect(self.dfii.master, self.ddrphy.dfi)

		#
		# LASMI
		#
		self.submodules.lasmicon = lasmicon.LASMIcon(self.ddrphy.phy_settings, sdram_geom, sdram_timing)
		self.submodules.dficon1 = dfi.Interconnect(self.lasmicon.dfi, self.dfii.slave)

		n_lasmims = 1 # wishbone bridging
		if platform_name == "mixxeo":
			n_lasmims += 4 # framebuffer (2-channel mixing) + 2 DVI samplers
		if platform_name == "m1":
			n_lasmims += 1 # framebuffer (single channel)
		if with_memtest:
			n_lasmims += 2 # writer + reader
		self.submodules.lasmixbar = lasmibus.Crossbar([self.lasmicon.lasmic], n_lasmims, self.lasmicon.nrowbits)

		lasmims = list(self.lasmixbar.masters)
		lasmim_wb = lasmims.pop()
		if platform_name == "mixxeo":
			lasmim_fb0, lasmim_fb1, lasmim_dvi0, lasmim_dvi1 = (lasmims.pop() for i in range(4))
		if platform_name == "m1":
			lasmim_fb = lasmims.pop()
		if with_memtest:
			lasmim_mtw, lasmim_mtr = lasmims.pop(), lasmims.pop()
		assert(not lasmims)

		#
		# WISHBONE
		#
		self.submodules.cpu = lm32.LM32()
		self.submodules.norflash = norflash.NorFlash(platform.request("norflash"), 12)
		self.submodules.sram = wishbone.SRAM(sram_size)
		self.submodules.minimac = minimac3.MiniMAC(platform.request("eth"))
		self.submodules.wishbone2lasmi = wishbone2lasmi.WB2LASMI(l2_size//4, lasmim_wb)
		self.submodules.wishbone2csr = 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)
		self.submodules.wishbonecon = wishbone.InterconnectShared(
			[
				self.cpu.ibus,
				self.cpu.dbus
			], [
				(lambda a: a[26:29] == 0, self.norflash.bus),
				(lambda a: a[26:29] == 1, self.sram.bus),
				(lambda a: a[26:29] == 3, self.minimac.membus),
				(lambda a: a[27:29] == 2, self.wishbone2lasmi.wishbone),
				(lambda a: a[27:29] == 3, self.wishbone2csr.wishbone)
			],
			register=True)
		
		#
		# CSR
		#
		self.submodules.crg = mxcrg.MXCRG(MXClockPads(platform), clk_freq)
		self.submodules.uart = uart.UART(platform.request("serial"), clk_freq, baud=115200)
		self.submodules.identifier = identifier.Identifier(0x4D31, version, int(clk_freq))
		self.submodules.timer0 = timer.Timer()
		if platform_name == "mixxeo":
			self.submodules.leds = gpio.GPIOOut(platform.request("user_led"))
			self.submodules.fb = framebuffer.MixFramebuffer(platform.request("vga_out"), platform.request("dvi_out"),
				lasmim_fb0, lasmim_fb1)
			self.submodules.dvisampler0 = dvisampler.DVISampler(platform.request("dvi_in", 0), lasmim_dvi0)
			self.submodules.dvisampler1 = dvisampler.DVISampler(platform.request("dvi_in", 1), lasmim_dvi1)
		if platform_name == "m1":
			self.submodules.buttons = gpio.GPIOIn(Cat(platform.request("user_btn", 0), platform.request("user_btn", 2)))
			self.submodules.leds = gpio.GPIOOut(Cat(*[platform.request("user_led", i) for i in range(2)]))
			self.submodules.fb = framebuffer.Framebuffer(platform.request("vga"), None, lasmim_fb)
		if with_memtest:
			self.submodules.memtest_w = memtest.MemtestWriter(lasmim_mtw)
			self.submodules.memtest_r = memtest.MemtestReader(lasmim_mtr)

		self.submodules.csrbankarray = csrgen.BankArray(self,
			lambda name, memory: self.csr_map[name if memory is None else name + "_" + memory.name_override])
		self.submodules.csrcon = csr.Interconnect(self.wishbone2csr.csr, self.csrbankarray.get_buses())

		#
		# Interrupts
		#
		for k, v in sorted(self.interrupt_map.items(), key=itemgetter(1)):
			if hasattr(self, k):
				self.comb += self.cpu.interrupt[v].eq(getattr(self, k).ev.irq)

		#
		# Clocking
		#
		self.comb += [
			self.ddrphy.clk4x_wr_strb.eq(self.crg.clk4x_wr_strb),
			self.ddrphy.clk4x_rd_strb.eq(self.crg.clk4x_rd_strb)
		]