humpback-dds/migen/fpga_config.py

from humpback import HumpbackPlatform
from migen.fhdl.module import Module

class UrukulConnector(Module):
	def __init__(self, platform):
		# Request EEM I/O & SPI
		eem = platform.request("eem", 0)
		spi = platform.request("spi")
		led = platform.request("user_led")

		# Assert signal length
		assert len(eem.p) == 8
		assert len(eem.n) == 8
		assert len(spi.sclk) == 1
		assert len(spi.mosi) == 1
		assert len(spi.miso) == 1
		assert len(spi.cs) == 3

		# Flip positive signal as negative output, maybe only do it for FPGA outputs
		# self.comb += eem.n.eq(~eem.p)

		# Link EEM to SPI
		self.comb += [

			eem.p[0].eq(spi.sclk),
			eem.n[0].eq(~spi.sclk),

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

			spi.miso.eq(eem.p[2]),

			eem.p[3].eq(spi.cs[0]),
			eem.n[3].eq(~spi.cs[0]),

			eem.p[4].eq(spi.cs[1]),
			eem.n[4].eq(~spi.cs[1]),

			eem.p[5].eq(spi.cs[2]),
			eem.n[5].eq(~spi.cs[2]),

			led.eq(1)
		]

		# Debug purposes: Tie EEM MISO to EEM MOSI
		# self.comb += eem.p[2].eq(eem.p[1])


if __name__ == "__main__":
	platform = HumpbackPlatform()
	platform.build(UrukulConnector(platform))