applet.interface.gpib_controller: new applet.

software/glasgow/applet/interface/gpib_controller/__init__.py

@@ -0,0 +1,168 @@
+import logging
+from amaranth import *
+from amaranth.lib.cdc import FFSynchronizer
+from amaranth.lib.wiring import Component, In, Out
+
+from ....support.logging import *
+from ... import *
+
+
+# class GPIBDeviceBus(Component):
+#     # Data lines
+#     doe  : In()
+#     do   : In(8)
+#     di   : Out(8)
+
+
+
+
+# class GPIBControllerBus(Component):
+
+#     # Control lines
+#     eoi  : In() # End or Identify
+#     dav  : In() # Data Valid            \
+#     nrfd : Out() # Not Ready For Data    |  Handshake bus
+#     ndac : Out() # No Data Accepted      /
+#     ifc  : Signal() # Interface Clear    \
+#     srq  : Signal() # Service Request    |  Management bus
+#     atn  : Signal() # Attention          /
+#     ren  : Signal() # Remote Enable
+
+
+#     def __init__(self, pads):
+#         self.pads = pads
+
+#         # Data lines
+#         self.doe  = Signal()
+#         self.do   = Signal(8)
+#         self.di   = Signal(8)
+
+#         # Control lines
+#         self.eoi  = Signal() # End or Identify
+#         self.dav  = Signal() # Data Valid            \
+#         self.nrfd = Signal() # Not Ready For Data    |  Handshake bus
+#         self.ndac = Signal() # No Data Accepted      /
+#         self.ifc  = Signal() # Interface Clear    \
+#         self.srq  = Signal() # Service Request    |  Management bus
+#         self.atn  = Signal() # Attention          /
+#         self.ren  = Signal() # Remote Enable
+
+#     def elaborate(self, platform):
+#         m = Module()
+
+#         m.d.comb += [
+#             # Data lines
+#             self.pads.dio_t.oe.eq(self.doe),
+#             self.pads.dio_t.o.eq(self.do),
+#             self.pads.dio_t.i.eq(self.di),
+
+#             # Control lines
+#             self.pads.eoi_t.oe.eq(1),
+#             self.pads.
+#         ]
+
+#         return m
+
+
+class GPIBControllerSubtarget(Elaboratable):
+    def elaborate(self, platform):
+        m = Module()
+        return m
+
+
+class GPIBControllerInterface:
+    def __init__(self, interface, logger):
+        self.lower   = interface
+        self._logger = logger
+        self._level  = logging.DEBUG if self._logger.name == __name__ else logging.TRACE
+
+    async def reset(self):
+        self._logger.debug("GPIB: reset")
+        await self.lower.reset()
+
+
+class GPIBControllerApplet(GlasgowApplet):
+    logger = logging.getLogger(__name__)
+    help = "control, talk, and listen to devices on the GPIB (née HP-IB) instrumentation bus"
+    description = """
+    Control, talk, and listen to devices on the IEEE 488.1 bus, known as GPIB or HP-IB. This bus
+    is typically used to remotely control instrumentation, such as multimeters, oscilloscopes,
+    frequency generators, and so on, though it is also used for some historic computer peripherals.
+
+    The GPIB connector is wired as follows (front view of plug/cable side):
+
+    ::
+        _______________________________________________________________________
+        \\                                                                     /
+         \\    DIO1 DIO2 DIO3 DIO4 EOI  DAV  NRFD NDAC IFC  SRQ  ATN  Shld    /
+          \\     1    2    3    4    5    6    7    8    9   10   11   12    /
+           \\   24   23   22   21   20   19   18   17   16   15   14   13   /
+            \\ GND  GND  GND  GND  GND  GND  GND  REN DIO8  DIO7 DIO6 DIO5 /
+             \\___________________________________________________________/
+
+    With the default pin configuration for this applet, the device pins 1..16 should be wired to
+    the male GPIB connector pins in this sequence:
+
+        1, 2, 3, 4, 13, 14, 15, 16, 6, 7, 8, 9, 11, 5, 10, 17
+    """
+    required_revision = "C0"
+
+    __pins = ("dav", "nrfd", "ndac", "ifc", "atn", "eoi", "srq", "ren")
+    __pin_sets = ("dio",)
+
+    @classmethod
+    def add_build_arguments(cls, parser, access):
+        super().add_build_arguments(parser, access)
+
+        # IEEE Std 488.1-2003 §7.1:
+        # Selection of a minimum set of interface functions from Clause 4 leads to the following
+        # minimum set of signal lines in order to be system compatible:
+        # a) DIO 1–7
+        # b) DAV, NRFD, NDAC
+        # c) IFC and ATN (unnecessary in systems without a controller)
+
+        # Required pins first.
+        access.add_pin_set_argument(parser, "dio", range(7, 9), default=8, required=True)
+        access.add_pin_argument(parser, "dav",  default=True, required=True)
+        access.add_pin_argument(parser, "nrfd", default=True, required=True)
+        access.add_pin_argument(parser, "ndac", default=True, required=True)
+        # Non-required pins second.
+        access.add_pin_argument(parser, "ifc", default=True)
+        access.add_pin_argument(parser, "atn", default=True)
+        access.add_pin_argument(parser, "eoi", default=True)
+        access.add_pin_argument(parser, "srq", default=True)
+        access.add_pin_argument(parser, "ren", default=True)
+
+    def build(self, target, args):
+        self.mux_interface = iface = target.multiplexer.claim_interface(self, args)
+        iface.add_subtarget(GPIBControllerSubtarget(
+            pads=iface.get_pads(args, pins=self.__pins, pin_sets=self.__pin_sets),
+            out_fifo=iface.get_out_fifo(),
+            in_fifo=iface.get_in_fifo()
+        ))
+
+    @classmethod
+    def add_run_arguments(cls, parser, access):
+        pass # None of the parameters are configurable.
+
+    async def run(self, device, args):
+        # Although running GPIB on 3.3 V would be in-spec, none of the devices likely to have it
+        # will use anything but 5 V, and so we don't need this to be configurable.
+        await device.set_voltage(args.port, 5.0)
+
+        iface = await device.demultiplexer.claim_interface(
+            self, self.mux_interface, args,
+            # Strictly speaking only NRFD, NDAC, and SRQ need to be pulled up; however there is no
+            # harm in enabling the built-in ~10k pullups on every line, and this can help avoid
+            # glitches in the complicated GPIB message coding state machines.
+            pull_high=self.__pins + self.__pin_sets)
+        gpib_iface = GPIBControllerInterface(iface, self.logger)
+        return gpib_iface
+
+
+# -------------------------------------------------------------------------------------------------
+
+class GPIBControllerAppletTestCase(GlasgowAppletTestCase, applet=GPIBControllerApplet):
+    @synthesis_test
+    def test_build(self):
+        self.assertBuilds()

software/pyproject.toml

@@ -54,6 +54,7 @@ jtag-pinout = "glasgow.applet.interface.jtag_pinout:JTAGPinoutApplet"
 jtag-probe = "glasgow.applet.interface.jtag_probe:JTAGProbeApplet"
 jtag-openocd = "glasgow.applet.interface.jtag_openocd:JTAGOpenOCDApplet"
 jtag-svf = "glasgow.applet.interface.jtag_svf:JTAGSVFApplet"
+gpib-controller = "glasgow.applet.interface.gpib_controller:GPIBControllerApplet"
 ps2-host = "glasgow.applet.interface.ps2_host:PS2HostApplet"
 sbw-probe = "glasgow.applet.interface.sbw_probe:SpyBiWireProbeApplet"