icebreaker: Add optional DVI Video Terminal with new LiteX's VideoOut core.

Tested with: ./icebreaker.py --cpu-type=serv --with-video-terminal --build --flash

https://twitter.com/enjoy_digital/status/1365324823447171074

litex_boards/platforms/icebreaker.py

@@ -83,6 +83,19 @@ break_off_pmod = [
      ("user_ledg", 3, Pins("PMOD2:2"), IOStandard("LVCMOS33"))
 ]
 
+dvi_pmod = [
+    ("dvi", 0,
+        Subsignal("clk",   Pins("PMOD1B:1")),
+        Subsignal("de",    Pins("PMOD1B:6")),
+        Subsignal("hsync", Pins("PMOD1B:3")),
+        Subsignal("vsync", Pins("PMOD1B:7")),
+        Subsignal("r",     Pins("PMOD1A:5 PMOD1A:1 PMOD1A:4 PMOD1A:0")),
+        Subsignal("g",     Pins("PMOD1A:7 PMOD1A:3 PMOD1A:6 PMOD1A:2")),
+        Subsignal("b",     Pins("PMOD1B:2 PMOD1B:5 PMOD1B:4 PMOD1B:0")),
+        IOStandard("LVCMOS33"),
+    )
+]
+
 # Platform -----------------------------------------------------------------------------------------
 
 class Platform(LatticePlatform):

litex_boards/targets/icebreaker.py

@@ -32,6 +32,7 @@ from litex.soc.integration.soc_core import *
 from litex.soc.integration.soc import SoCRegion
 from litex.soc.integration.builder import *
 from litex.soc.cores.led import LedChaser
+from litex.soc.cores.video import *
 
 kB = 1024
 mB = 1024*kB
@@ -69,7 +70,7 @@ class _CRG(Module):
 
 class BaseSoC(SoCCore):
     mem_map = {**SoCCore.mem_map, **{"spiflash": 0x80000000}}
-    def __init__(self, bios_flash_offset, sys_clk_freq=int(24e6), **kwargs):
+    def __init__(self, bios_flash_offset, sys_clk_freq=int(24e6), with_video_terminal=False, **kwargs):
         platform = icebreaker.Platform()
         platform.add_extension(icebreaker.break_off_pmod)
 
@@ -77,6 +78,10 @@ class BaseSoC(SoCCore):
         kwargs["integrated_sram_size"] = 0
         kwargs["integrated_rom_size"]  = 0
 
+        # Force sys_clk_freq with Video Terminal since iCE40's PLL only has 1 output.
+        if with_video_terminal:
+            sys_clk_freq = 40e6
+
         # Set CPU variant / reset address
         kwargs["cpu_reset_address"] = self.mem_map["spiflash"] + bios_flash_offset
 
@@ -90,8 +95,8 @@ class BaseSoC(SoCCore):
         self.submodules.crg = _CRG(platform, sys_clk_freq)
 
         # 128KB SPRAM (used as SRAM) ---------------------------------------------------------------
-        self.submodules.spram = Up5kSPRAM(size=128*kB)
-        self.bus.add_slave("sram", self.spram.bus, SoCRegion(size=128*kB))
+        self.submodules.spram = Up5kSPRAM(size=64*kB)
+        self.bus.add_slave("sram", self.spram.bus, SoCRegion(size=64*kB))
 
         # SPI Flash --------------------------------------------------------------------------------
         self.add_spi_flash(mode="1x", dummy_cycles=8)
@@ -103,6 +108,24 @@ class BaseSoC(SoCCore):
             linker = True)
         )
 
+        # Video Terminal ---------------------------------------------------------------------------
+        if with_video_terminal:
+            self.platform.add_extension(icebreaker.dvi_pmod)
+            self.submodules.vtg = vtg = VideoTimingGenerator(default_video_timings="800x600@60Hz")
+            self.add_csr("vtg")
+            #self.submodules.vgen = vgen = ColorBarsPattern()
+            self.submodules.vgen = vgen = VideoTerminal(hres=800, vres=600)
+            self.submodules.vphy = vphy = VideoDVIPHY(platform.request("dvi"), clock_domain="sys")
+            self.comb += [
+                # Connect UART to Video Terminal.
+                vgen.uart_sink.valid.eq(self.uart.source.valid & self.uart.source.ready),
+                vgen.uart_sink.data.eq(self.uart.source.data),
+                # Connect Video Timing Generator to Video Terminal.
+                vtg.source.connect(vgen.vtg_sink),
+                # Connect VideoTerminal to VideoDVIPHY.
+                vgen.source.connect(vphy.sink),
+            ]
+
         # Leds -------------------------------------------------------------------------------------
         self.submodules.leds = LedChaser(
             pads         = platform.request_all("user_led"),
@@ -127,6 +150,7 @@ def main():
     parser.add_argument("--flash",               action="store_true", help="Flash Bitstream")
     parser.add_argument("--sys-clk-freq",        default=24e6,        help="System clock frequency (default: 24MHz)")
     parser.add_argument("--bios-flash-offset",   default=0x40000,     help="BIOS offset in SPI Flash (default: 0x40000)")
+    parser.add_argument("--with-video-terminal", action="store_true", help="Enable Video Terminal (with DVI PMOD)")
     builder_args(parser)
     soc_core_args(parser)
     args = parser.parse_args()
@@ -134,6 +158,7 @@ def main():
     soc = BaseSoC(
         bios_flash_offset   = args.bios_flash_offset,
         sys_clk_freq        = int(float(args.sys_clk_freq)),
+        with_video_terminal = args.with_video_terminal,
         **soc_core_argdict(args)
     )
     builder = Builder(soc, **builder_argdict(args))