tests: gateware: peripherals: Started adding the CPOL Low tests and s…

…lowly working the kinks out

tests/gateware/peripherals/test_spi.py

@@ -76,6 +76,79 @@ def test_spi_controller(self):
 		yield Settle()
 		yield
 
+class SPIControllerCLKLowTests(ToriiTestCase):
+	dut: SPIController = SPIController
+	dut_args = {
+		'clk': clk, 'cipo': cipo, 'copi': copi, 'cs': cs, 'cpol': SPICPOL.LOW
+	}
+	platform = MockPlatform()
+
+	def send_recv(self, d_out, d_in, ovlp = False):
+		self.assertEqual((yield clk), 0)
+		yield self.dut.wdat.eq(d_out)
+		yield self.dut.xfr.eq(1)
+		yield Settle()
+		yield
+		self.assertEqual((yield clk), 0)
+		yield self.dut.xfr.eq(0)
+		yield Settle()
+		yield
+		self.assertEqual((yield clk), 0)
+		yield cipo.eq((d_in >> 6) & 1)
+		yield Settle()
+		yield
+		self.assertEqual((yield clk), 0)
+		self.assertEqual((yield copi), ((d_out >> 6) & 1))
+		yield Settle()
+		yield
+		for bit in range(1, 7):
+			self.assertEqual((yield clk), 1)
+			yield cipo.eq((d_in >> (7 - bit)) & 1)
+			yield Settle()
+			yield
+			self.assertEqual((yield clk), 0)
+			self.assertEqual((yield copi), ((d_out >> (7 - bit)) & 1))
+			yield Settle()
+			yield
+		self.assertEqual((yield clk), 1)
+		yield Settle()
+		yield
+		yield Settle()
+		yield
+		self.assertEqual((yield self.dut.done), 1)
+		if not ovlp:
+			yield Settle()
+			yield
+			self.assertEqual((yield clk), 1)
+			self.assertEqual((yield self.dut.done), 0)
+			self.assertEqual((yield self.dut.rdat), d_in)
+		yield Settle()
+
+	@ToriiTestCase.simulation
+	@ToriiTestCase.sync_domain(domain = 'sync')
+	def test_spi_controller(self):
+		yield
+		self.assertEqual((yield clk), 0)
+		yield self.dut.cs.eq(1)
+		yield Settle()
+		yield
+		yield from self.send_recv(0x0F, 0xF0)
+		yield
+		self.assertEqual((yield clk), 0)
+		yield self.dut.cs.eq(0)
+		yield Settle()
+		yield
+		self.assertEqual((yield clk), 0)
+		yield self.dut.cs.eq(1)
+		yield Settle()
+		yield
+		yield from self.send_recv(0xAA, 0x55, ovlp = True)
+		yield from self.send_recv(0x55, 0xAA, ovlp = False)
+		yield
+		yield self.dut.cs.eq(0)
+		yield Settle()
+		yield
+
 
 class TestRegisters(Multiplexer):
 	def __init__(self, *, name: str | None = None) -> None: