humpback-dds/migen/fpga_config.py

# Import built in I/O, Connectors & Platform template for Humpback
from migen.build.platforms.sinara import humpback
# Import migen platform for Lattice Products
from migen.build.lattice import LatticePlatform
# Import migen pin record structure
from migen.build.generic_platform import *
from migen.fhdl.module import Module
from migen.fhdl.specials import Instance
from migen.genlib.io import *
from migen.build.lattice.common import LatticeiCE40DifferentialInputImpl
from migen.genlib.io import DifferentialInput

spi_cs = [
	("spi_cs", 0, Pins("B13 B14 B15"), IOStandard("LVCMOS33"))
]
io_update = [
	("io_update", 0, Pins("A11"), IOStandard("LVCMOS33"))
]

class UrukulConnector(Module):
	def __init__(self, platform):
		# Request EEM I/O & SPI
		eem0 = [
			platform.request("eem0", 0),
			platform.request("eem0", 1),
			# Supply EEM pin with negative polarity
			# See issue/PR: https://github.com/m-labs/migen/pull/181
			platform.request("eem0_n", 2),
			platform.request("eem0", 3),
			platform.request("eem0", 4),
			platform.request("eem0", 5),
			platform.request("eem0", 6)
		]
		spi = platform.request("spi")
		spi_cs = platform.request("spi_cs")
		led = platform.request("user_led")
		io_update = platform.request("io_update")

		assert len(spi.clk) == 1
		assert len(spi.mosi) == 1
		assert len(spi.miso) == 1
		assert len(spi_cs) == 3
		assert len(io_update) == 1

		# Flip negative input to positive output
		self.miso_n = Signal()

		# Very similar setup to Diff setup for iCE40 suggested, but gave B pin instead
		self.specials += Instance("SB_IO",
							p_PIN_TYPE=C(0b000001, 6),
							p_IO_STANDARD="SB_LVDS_INPUT",
							io_PACKAGE_PIN=eem0[2],
							o_D_IN_0=self.miso_n
						)

		# Link EEM to SPI
		self.comb += [

			eem0[0].p.eq(spi.clk),
			eem0[0].n.eq(~spi.clk),

			eem0[1].p.eq(spi.mosi),
			eem0[1].n.eq(~spi.mosi),

			spi.miso.eq(~self.miso_n),

			eem0[3].p.eq(spi_cs[0]),
			eem0[3].n.eq(~spi_cs[0]),

			eem0[4].p.eq(spi_cs[1]),
			eem0[4].n.eq(~spi_cs[1]),

			eem0[5].p.eq(spi_cs[2]),
			eem0[5].n.eq(~spi_cs[2]),

			eem0[6].p.eq(io_update),
			eem0[6].n.eq(~io_update),

			led.eq(1)
		]


if __name__ == "__main__":
	platform = humpback.Platform()
	platform.add_extension(spi_cs)
	platform.add_extension(io_update)
	platform.build(UrukulConnector(platform))