FPGA breakout support

Author: psychogenic

src/ttboard/boot/demoboard_detect.py

@@ -31,6 +31,12 @@ def to_string(cls, v:int):
         if v in asStr:
             return asStr[v]
         return 'N/A'
+    
+class DemoboardCarrier:
+    UNKNOWN = 0
+    TT_CARRIER = 1
+    FPGA = 2
+    
 
 class DemoboardDetect:
     '''
@@ -88,7 +94,16 @@ def probe_pullups(cls):
             log.info("TT06+ demoboard with carrier present")
             cls.PCB = DemoboardVersion.TT06
             cls.CarrierPresent = True
+            cls.CarrierVersion = DemoboardCarrier.TT_CARRIER
+            return True
+        
+        if (crst) and (not cena):
+            log.info("ctrl mux lines pulled to indicate TT06+ compatible FPGA board")
+            cls.PCB = DemoboardVersion.TT06
+            cls.CarrierPresent = True
+            cls.CarrierVersion = DemoboardCarrier.FPGA
             return True
+            
 
         if crst and cena:
             log.info("probing ctrl mux lines gives no info, unable to determine db version")
@@ -113,6 +128,7 @@ def probe_tt04mux(cls):
         if mux_1 != mux_0:
             log.info("DB seems to have on-board MUX: TT04+")
             cls.PCB = DemoboardVersion.TT04
+            cls.CarrierVersion = DemoboardCarrier.TT_CARRIER
             return True
 
         log.debug("Mux twiddle has no effect, probably not TT04 db")

src/ttboard/boot/rom.py

@@ -7,6 +7,7 @@
 
 import ttboard.util.time as time
 from ttboard.boot.shuttle_properties import ShuttleProperties
+from ttboard.boot.demoboard_detect import DemoboardDetect, DemoboardCarrier
 
 
 import ttboard.log as logging
@@ -55,14 +56,24 @@ def contents(self):
         if self._contents is not None:
             return self._contents 
 
-        # select project 0
-        self.project_mux.reset_and_clock_mux(0)
-        
         self._contents = {
                 'shuttle': 'unknown',
                 'repo': '',
                 'commit': ''
         }
+        if not DemoboardDetect.CarrierPresent:
+            log.warn("No carrier present, skipping chiprom")
+            return self._contents
+        
+        if DemoboardDetect.CarrierVersion != DemoboardCarrier.TT_CARRIER:
+            if DemoboardDetect.CarrierVersion == DemoboardCarrier.FPGA:
+                self._contents['shuttle'] = 'FPGA'
+            
+            return self._contents
+        
+        # select project 0
+        self.project_mux.reset_and_clock_mux(0)
+        
 
         # list of expected outputs as
         # (SEND, RCV)

src/ttboard/demoboard.py

@@ -23,7 +23,7 @@
 from ttboard.project_mux import Design
 from ttboard.config.user_config import UserConfig
 import ttboard.util.platform as platform 
-from ttboard.boot.demoboard_detect import DemoboardDetect, DemoboardVersion
+from ttboard.boot.demoboard_detect import DemoboardDetect, DemoboardVersion, DemoboardCarrier
 
 import ttboard.log as logging
 log = logging.getLogger(__name__)
@@ -101,15 +101,20 @@ def __init__(self,
         if log_level is not None:
             logging.basicConfig(level=log_level)
 
-        if mode is not None:
-            self.default_mode = mode 
+        if DemoboardDetect.CarrierVersion == DemoboardCarrier.FPGA:
+            log.info(f'Demoboard hosting an FPGA, setting mode to manual inputs')
+            mode = RPMode.ASIC_MANUAL_INPUTS
         else:
-            self.default_mode = self.user_config.default_mode
-            if self.default_mode is None:
-                # neither arg and ini file specify mode
-                raise AttributeError('MUST specify either mode in .ini DEFAULT or mode argument')
+            if mode is not None:
+                self.default_mode = mode 
+            else:
+                self.default_mode = self.user_config.default_mode
+                if self.default_mode is None:
+                    # neither arg and ini file specify mode
+                    raise AttributeError('MUST specify either mode in .ini DEFAULT or mode argument')
+                
+                mode = self.default_mode
 
-            mode = self.default_mode
 
         log.info(f'Demoboard starting up in mode {RPMode.to_string(mode)}')