update tests

src/groovylight/bitslicer.py

@@ -70,6 +70,7 @@ class Hub75Data(wiring.Signature):
             }
         )
 
+
 class SwapBuffer(wiring.Component):
     """A pair of BRAMs for holdling line data that are swapped between using an external signal.
 
@@ -129,7 +130,6 @@ class SwapBuffer(wiring.Component):
             # self.write_port.data.eq(Mux(self.selector, write0.data, write1.data)),
             write0.data.eq(self.write_port.data),
             write1.data.eq(self.write_port.data),
-
             read0.addr.eq(self.read_port.addr),
             read1.addr.eq(self.read_port.addr),
             read0.en.eq(~self.selector),
@@ -141,63 +141,49 @@ class SwapBuffer(wiring.Component):
 
 
 class Hub75StringDriver(wiring.Component):
-    """A data driver for Hub75 panels. This accesses the line memory and feeds out the data"""
+    """A data driver for Hub75 panels. This accesses the line memory and feeds out the data.
+    It is controlled by a Hub75Coordinator to signal when it should run and what bit of the data
+    it should send.
+    """
 
     bcm_select: In(3)
     done: Out(1)
     start: In(1)
-    active_bank: In(1)  # the bank to use
+    bram_port: In(ReadPort.Signature(addr_width=9, shape=Rgb888Layout))
-    bram_port: Out(WritePort.Signature(
-        addr_width=9, shape=Rgb888Layout
-    )) # the other line to be swapped to.
     display_out: Out(Hub75Data())  # data signal output.
 
+    def __init__(self, panel_length: int = 128, *, src_loc_at=0):
+        self.panel_length = panel_length
+        super().__init__(None, src_loc_at=src_loc_at)
+
     def elaborate(self, platform: Platform) -> Module:
         m = Module()
 
         # add two memories
-        m.submodules.bram0 = bram0 = Memory(shape=Rgb888Layout, depth=512, init=[])
-        m.submodules.bram1 = bram1 = Memory(shape=Rgb888Layout, depth=512, init=[])
 
-        # We use two brams here so we can swap between each - that way we can update the data
+        self._counter = counter = Signal(32)
-        # while displaying the other line. Switching is controlled by the coordinator.
-
-        readports = Mux([bram0.read_port(), bram1.read_port()])
-        active_readport = readports[self.active_bank]
-        m.d.comb += active_readport.eq(readports[self.active_bank])
-        writeports = Array([bram0.write_port(), bram1.write_port()])
-        m.d.comb += self.bram_port.eq(writeports[~self.active_bank])
-
-        # We want to set up the bram ports
-        port0 = bram0.read_port()
-        port1 = bram1.read_port()
-        # the enable for these ports is based on active bank.
-        m.d.comb += port0.en.eq(self.active_bank)
-        m.d.comb += port1.en.eq(~self.active_bank)
-
-        counter = Signal(32)
         m.d.sync += counter.eq(counter + 1)
 
         ram_rgb_slice = Cat(
-            active_readport.data["red"].bit_select(self.bcm_shift, 1),
+            self.bram_port.data["red"].bit_select(self.bcm_select, 1),
-            active_readport.data["blue"].bit_select(self.bcm_shift, 1),
+            self.bram_port.data["blue"].bit_select(self.bcm_select, 1),
-            active_readport.data["green"].bit_select(self.bcm_shift, 1),
+            self.bram_port.data["green"].bit_select(self.bcm_select, 1),
         )
 
-        pixnum = Signal(8, reset=127)
+        pixnum = Signal(range(self.panel_length), init=self.panel_length - 1)
-        pixrow = Signal(1, reset=0)
+        pixrow = Signal(1, init=0)
-        m.d.comb += self.buf_addr.eq(Cat(pixrow, pixnum))
+        m.d.comb += self.bram_port.addr.eq(Cat(pixrow, pixnum))
 
         with m.FSM():
             with m.State("init"):
                 m.d.sync += [
                     self.done.eq(0),
                     counter.eq(0),
-                    pixnum.eq(127),
+                    pixnum.eq(self.panel_length - 1),
                     pixrow.eq(0),
                 ]
                 with m.If(self.start == 1):
-                    m.d.sync += active_readport.en.eq(1)
+                    m.d.sync += self.bram_port.en.eq(1)
                     m.next = "prefetch"
             with m.State("prefetch"):
                 with m.If(counter == 0):
@@ -209,23 +195,32 @@ class Hub75StringDriver(wiring.Component):
                 with m.Elif(counter == 3):
                     m.d.sync += [self.display_out.rgb1.eq(ram_rgb_slice), counter.eq(0)]
                     m.next = "writerow"
+            with m.State("writerow"):
+                with m.If(counter[0:1] == 0):
+                    # rising edge of the clock
+                    m.d.sync += pixrow.eq(0)
+
+                with m.If(counter[0:1] == 1):
+                    m.d.sync += [
+                        pixrow.eq(1),
+                        self.display_out.rgb0.eq(ram_rgb_slice),
+                    ]
+                with m.If(counter[0:1] == 2):
+                    m.d.sync += [
+                        pixnum.eq(pixnum - 1),
+                        pixrow.eq(0),
+                        self.display_out.rgb1.eq(ram_rgb_slice),
+                    ]
+                with m.If(counter == 128 * 2 + 1):
+
+                    m.next = "done"
+            with m.State("done"):
+                m.d.sync += self.done.eq(1)
+                m.next = "init"
 
         return m
 
 
-def test_stringdriver():
-    dut = Hub75StringDriver()
-    sim = Simulator(dut)
-    sim.add_clock(1e-6)
-
-    async def testbench(ctx):
-        pass
-
-    sim.add_testbench(testbench)
-    with sim.write_vcd("output.vcd"):
-        sim.run_until(1e-6 * 1000)
-
-
 class Hub75Coordinator(wiring.Component):
     """A shared-control hub75 driver"""
 

src/groovylight/test_hub75.py

@@ -0,0 +1,37 @@
+from amaranth import Array, Module, Cat, Signal, Assert, unsigned
+from amaranth.build import Platform
+from amaranth.lib import wiring, data
+from amaranth.lib.wiring import In, Out
+from amaranth.lib.memory import Memory, WritePort
+from amaranth.sim import Simulator
+
+from .bitslicer import Hub75StringDriver, Rgb888Layout
+
+
+def test_stringdriver():
+    # the string driver test must 
+    # 1. finish
+    # 2. strobe through all of the data in the array
+    # 3. slice the correct bit from the data.
+    m = Module()
+    m.submodules.dut = dut = Hub75StringDriver()
+    m.submodules.mem = mem = Memory(shape=Rgb888Layout, depth=512, init=[])
+    port = mem.read_port()
+
+    wiring.connect(m, port, dut.bram_port)
+
+    async def testbench(ctx):
+        # select a bit, strobe start, read values, test against known.
+        ctx.set(dut.bcm_select, 5)
+        ctx.set(dut.start, 1)
+        await ctx.tick()
+        ctx.set(dut.start, 0)
+        assert(ctx.get(dut.bram_port.en) == 1)
+        pass
+
+    sim = Simulator(m)
+    sim.add_clock(1e-6)
+
+    with sim.write_vcd("output.vcd"):
+
+        sim.run_until(1e-6 * 1000)

src/groovylight/test_swapbuffer.py

@@ -28,6 +28,7 @@ def test_swapbuffer():
         await ctx.tick().repeat(2) # takes two clocks after switching selector to output data.
         assert ctx.get(dut.read_port.data) == test_color
     
+    # TODO: add more assertions/verification
     sim.add_testbench(testbench)
     with sim.write_vcd("output.vcd"):
         sim.run_until(1e-6 * 1000)