test: add test for SPI core using SD card

artiq/test/coredevice/test_spi.py

@@ -0,0 +1,61 @@
+import unittest
+from artiq.experiment import *
+from artiq.test.hardware_testbench import ExperimentCase
+from artiq.language.core import (kernel, delay_mu, delay)
+from artiq.language.units import us
+from artiq.coredevice import spi
+
+
+_SDCARD_SPI_CONFIG = (0*spi.SPI_OFFLINE | 0*spi.SPI_CS_POLARITY |
+                      0*spi.SPI_CLK_POLARITY | 0*spi.SPI_CLK_PHASE |
+                      0*spi.SPI_LSB_FIRST | 0*spi.SPI_HALF_DUPLEX)
+
+class CardTest(EnvExperiment):
+    def build(self):
+        self.setattr_device("core")
+        self.setattr_device("spi_mmc")
+
+    @kernel
+    def run(self):
+        self.core.reset()
+        self.core.break_realtime()
+        response = 0xff
+        self.spi_mmc.set_config(_SDCARD_SPI_CONFIG, 500*kHz, 500*kHz)
+        self.spi_mmc.set_xfer(0, 8, 0)
+
+        for i in range(10):
+            self.spi_mmc.write(0xffffffff)
+            delay(-5*us)
+
+        delay(100*us)
+
+        self.spi_mmc.set_xfer(1, 8, 0)
+        self.spi_mmc.write(0x40000000)
+        delay(-5*us)
+        self.spi_mmc.write(0x00000000)
+        delay(-5*us)
+        self.spi_mmc.write(0x00000000)
+        delay(-5*us)
+        self.spi_mmc.write(0x00000000)
+        delay(-5*us)
+        self.spi_mmc.write(0x00000000)
+        delay(-5*us)
+        self.spi_mmc.write(0x95000000)
+        delay(-5*us)
+
+        self.spi_mmc.set_xfer(1, 0, 24)
+        self.spi_mmc.write(0xffffffff)
+        response = self.spi_mmc.read_sync()
+
+        sd_response = False
+        for i in range(3):
+            if ((response >> 8*i) & 0x0000ff) == 0x01:
+                sd_response = True
+                break
+        self.set_dataset("sd_response", sd_response)
+
+
+class SDTest(ExperimentCase):
+    def test(self):
+        self.execute(CardTest)
+        self.assertTrue(self.dataset_mgr.get("sd_response"))