add rgbview with channel_slice operator

src/groovylight/common.py

@@ -1,4 +1,4 @@
-from amaranth import Array, unsigned
+from amaranth import unsigned, Cat
 from amaranth.lib import wiring, data
 from amaranth.lib.wiring import Out
 
@@ -13,6 +13,9 @@ class RGBLayout(data.StructLayout):
             }
         )
 
+    def __call__(self, value):
+        return RGBView(self, value)
+
 
 Rgb888Layout = RGBLayout(8, 8, 8)
 Rgb666Layout = RGBLayout(6, 6, 6)
@@ -20,6 +23,23 @@ Rgb666Layout = RGBLayout(6, 6, 6)
 Rgb111Layout = RGBLayout(1, 1, 1)
 
 
+class RGBView(data.View):
+
+    def channel_size(self) -> int:
+        return self.red.shape()
+    def channel_slice(self, bit: int) -> Rgb111Layout:
+        """Select bits from each channel and use it to form an Rgb111Layout.
+        This is useful for BCM stuff, since the bits are sliced to form a bitplane.
+        """
+        return Rgb111Layout(
+            Cat(
+                self.red.bit_select(bit, 1),
+                self.green.bit_select(bit, 1),
+                self.blue.bit_select(bit, 1),
+            )
+        )
+
+
 class Hub75Stream(wiring.Signature):
     """A Hub75E Driver for a single string of panels."""
 

src/groovylight/hub75.py

@@ -122,29 +122,16 @@ class Hub75DataDriver(wiring.Component):
         if self.double_fetch:
             pixrow = Signal(1)
             m.d.comb += self.bram.addr.eq(Cat(pixrow, pixnum))
-            ram_rgb_slice = Cat(
+            ram_rgb_slice = self.bram.data.channel_slice(self.bcm_select)
-                self.bram.data["red"].bit_select(self.bcm_select, 1),
-                self.bram.data["blue"].bit_select(self.bcm_select, 1),
-                self.bram.data["green"].bit_select(self.bcm_select, 1),
-            )
         else:
+            m.d.comb += self.bram.addr.eq(pixnum)
             ram_rgb_slice = Array(
                 [
-                    Cat(
+                    self.bram.data[0].channel_slice(self.bcm_select),
-                        self.bram.data[0]["red"].bit_select(self.bcm_select, 1),
+                    self.bram.data[1].channel_slice(self.bcm_select),
-                        self.bram.data[0]["blue"].bit_select(self.bcm_select, 1),
-                        self.bram.data[0]["green"].bit_select(self.bcm_select, 1),
-                    ),
-                    Cat(
-                        self.bram.data[1]["red"].bit_select(self.bcm_select, 1),
-                        self.bram.data[1]["blue"].bit_select(self.bcm_select, 1),
-                        self.bram.data[1]["green"].bit_select(self.bcm_select, 1),
-                    ),
                 ]
             )
 
-            m.d.comb += self.bram.addr.eq(pixnum)
-
         with m.FSM():
             with m.State("init"):
                 m.d.sync += [
@@ -215,7 +202,7 @@ class Hub75StringDriver(wiring.Component):
                 "bcm_select": In(3),
                 "done": Out(1),
                 "start": In(1),
-                "bram_port": In(
+                "bram": In(
                     ReadPort.Signature(
                         addr_width=ceil_log2(panel_length),
                         shape=data.ArrayLayout(Rgb666Layout, 2),
@@ -232,16 +219,8 @@ class Hub75StringDriver(wiring.Component):
         self._counter = counter = Signal(32)  # unused count is optimized out
         m.d.sync += counter.eq(counter + 1)
 
-        ram_rgb0_slice = Cat(
+        ram_rgb0_slice = self.bram.data[0].channel_slice(self.bcm_select)
-            self.bram_port.data[0]["red"].bit_select(self.bcm_select, 1),
+        ram_rgb1_slice = self.bram.data[1].channel_slice(self.bcm_select)
-            self.bram_port.data[0]["blue"].bit_select(self.bcm_select, 1),
-            self.bram_port.data[0]["green"].bit_select(self.bcm_select, 1),
-        )
-        ram_rgb1_slice = Cat(
-            self.bram_port.data[1]["red"].bit_select(self.bcm_select, 1),
-            self.bram_port.data[1]["blue"].bit_select(self.bcm_select, 1),
-            self.bram_port.data[1]["green"].bit_select(self.bcm_select, 1),
-        )
         m.d.comb += [
             self.display_out.rgb0.eq(ram_rgb0_slice),
             self.display_out.rgb1.eq(ram_rgb1_slice),
@@ -249,7 +228,7 @@ class Hub75StringDriver(wiring.Component):
         m.d.sync += Assert(self.bcm_select < 6)
 
         pixnum = Signal(range(self.panel_length), init=self.panel_length - 1)
-        m.d.comb += self.bram_port.addr.eq(pixnum)
+        m.d.comb += self.bram.addr.eq(pixnum)
 
         with m.FSM():
             with m.State("init"):
@@ -259,7 +238,7 @@ class Hub75StringDriver(wiring.Component):
                     pixnum.eq(self.panel_length - 1),
                 ]
                 with m.If(self.start == 1):
-                    m.d.sync += self.bram_port.en.eq(1)
+                    m.d.sync += self.bram.en.eq(1)
                     m.next = "writerow"
             with m.State("writerow"):
                 with m.If(counter[0] == 0):
@@ -272,7 +251,7 @@ class Hub75StringDriver(wiring.Component):
                 with m.Else():
                     m.next = "done"
             with m.State("done"):
-                m.d.sync += [self.done.eq(1), self.bram_port.en.eq(0)]
+                m.d.sync += [self.done.eq(1), self.bram.en.eq(0)]
                 m.next = "init"
 
         return m

src/groovylight/tests/test_common.py

@@ -0,0 +1,23 @@
+from amaranth import unsigned
+import pytest
+
+from groovylight.common import Rgb888Layout, Rgb666Layout, RGBView
+
+
+def test_rgbview():
+    rgb = Rgb888Layout(0xAABBCC)
+
+    assert rgb.channel_size() == unsigned(8)
+
+    rgb18 = Rgb666Layout(0x2DEFD)
+
+    slice = rgb.channel_slice(1)
+    assert isinstance(slice, RGBView), "channel_slice should return another rgbview"
+
+    assert slice.channel_size() == unsigned(1), "channel_slice channel size should be 1"
+    assert isinstance(
+        rgb18.channel_slice(5), RGBView
+    ), "channel_slice should return another rgbview"
+
+    with pytest.raises(ValueError, match="Target of a view is 0 bit"):
+        rgb.channel_slice(8)

src/groovylight/tests/test_hub75.py

@@ -4,9 +4,14 @@ from amaranth.lib.memory import Memory
 from amaranth.sim import Simulator
 import pytest
 
-from groovylight.common import Rgb888Layout
+from groovylight.common import Rgb888Layout, Rgb666Layout
+
+from groovylight.hub75 import (
+    Hub75Coordinator,
+    Hub75DataDriver,
+    Hub75StringDriver,
+)
 
-from ..hub75 import Hub75Coordinator, Hub75DataDriver, Hub75StringDriver, Rgb666Layout
 
 
 def test_stringdriver():
@@ -21,7 +26,7 @@ def test_stringdriver():
     )
     port = mem.read_port()
 
-    wiring.connect(m, port, dut.bram_port)
+    wiring.connect(m, port, dut.bram)
 
     async def testbench(ctx):
         # select a bit, strobe start, read values, test against known.
@@ -29,7 +34,7 @@ def test_stringdriver():
         ctx.set(dut.start, 1)
         await ctx.tick()
         ctx.set(dut.start, 0)
-        assert ctx.get(dut.bram_port.en) == 1
+        assert ctx.get(dut.bram.en) == 1
         pass
 
     sim = Simulator(m)
@@ -57,8 +62,7 @@ def test_datadriver():
         ctx.set(dut.start, 1)
         await ctx.tick()
         ctx.set(dut.start, 0)
-        assert ctx.get(dut.bram_port.en) == 1
+        assert ctx.get(dut.bram.en) == 1
-        pass
 
     sim = Simulator(m)
     sim.add_clock(1e-6)