targets: add de0nano (100MHz, integrated bios and SDRAM)

targets/de0nano.py

@@ -0,0 +1,112 @@
+from migen.fhdl.std import *
+from migen.bus import wishbone
+
+from misoclib import uart, gpio, sdram
+from misoclib.sdram.phy import gensdrphy
+from misoclib.gensoc import SDRAMSoC
+
+class _PLL(Module):
+	def __init__(self, period_in, name, phase_shift, operation_mode):
+		self.clk_in = Signal()
+		self.clk_out = Signal()
+
+		self.specials += Instance("ALTPLL",
+			p_bandwidth_type = "AUTO",
+			p_clk0_divide_by = 1,
+			p_clk0_duty_cycle = 50,
+			p_clk0_multiply_by = 2,
+			p_clk0_phase_shift = "{}".format(str(phase_shift)),
+			p_compensate_clock = "CLK0",
+			p_inclk0_input_frequency = int(period_in*1000),
+			p_intended_device_family = "Cyclone IV E",
+			p_lpm_hint = "CBX_MODULE_PREFIX={}_pll".format(name),
+			p_lpm_type = "altpll",
+			p_operation_mode = operation_mode,
+			i_inclk=self.clk_in,
+			o_clk=self.clk_out,
+			i_areset=0,
+			i_clkena=0x3f,
+			i_clkswitch=0,
+			i_configupdate=0,
+			i_extclkena=0xf,
+			i_fbin=1,
+			i_pfdena=1,
+			i_phasecounterselect=0xf,
+			i_phasestep=1,
+			i_phaseupdown=1,
+			i_pllena=1,
+			i_scanaclr=0,
+			i_scanclk=0,
+			i_scanclkena=1,
+			i_scandata=0,
+			i_scanread=0,
+			i_scanwrite=0
+		)
+
+class _CRG(Module):
+	def __init__(self, platform):
+		self.clock_domains.cd_sys = ClockDomain()
+		self.clock_domains.cd_sys_ps = ClockDomain()
+		self.clock_domains.cd_por = ClockDomain(reset_less=True)
+
+		clk50 = platform.request("clk50")
+
+		sys_pll = _PLL(20, "sys", 0, "NORMAL")
+		self.submodules += sys_pll
+		self.comb += [
+			sys_pll.clk_in.eq(clk50),
+			self.cd_sys.clk.eq(sys_pll.clk_out)
+		]
+
+		sdram_pll = _PLL(20, "sdram", -3000, "ZERO_DELAY_BUFFER")
+		self.submodules += sdram_pll
+		self.comb += [
+			sdram_pll.clk_in.eq(clk50),
+			self.cd_sys_ps.clk.eq(sdram_pll.clk_out)
+		]
+
+		# Power on Reset (vendor agnostic)
+		rst_n = Signal()
+		self.sync.por += rst_n.eq(1)
+		self.comb += [
+			self.cd_por.clk.eq(self.cd_sys.clk),
+			self.cd_sys.rst.eq(~rst_n),
+			self.cd_sys_ps.rst.eq(~rst_n)
+		]
+
+		self.comb += platform.request("sdram_clock").eq(self.cd_sys_ps.clk)
+
+class BaseSoC(SDRAMSoC):
+	default_platform = "de0nano"
+
+	def __init__(self, platform, **kwargs):
+		SDRAMSoC.__init__(self, platform,
+			clk_freq=100*1000000,
+			with_rom=True,
+			**kwargs)
+
+		sdram_geom = sdram.GeomSettings(
+			bank_a=2,
+			row_a=13,
+			col_a=9
+		)
+
+		sdram_timing = sdram.TimingSettings(
+			tRP=self.ns(20),
+			tRCD=self.ns(20),
+			tWR=self.ns(20),
+			tWTR=2,
+			tREFI=self.ns(7800, False),
+			tRFC=self.ns(70),
+
+			req_queue_size=8,
+			read_time=32,
+			write_time=16
+		)
+
+		self.submodules.crg = _CRG(platform)
+
+		self.submodules.sdrphy = gensdrphy.GENSDRPHY(platform.request("sdram"))
+		self.register_sdram_phy(self.sdrphy.dfi, self.sdrphy.phy_settings, sdram_geom, sdram_timing)
+
+default_subtarget = BaseSoC