runtime: support clock switching

artiq/coredevice/comm_serial.py

@@ -7,6 +7,7 @@ from fractions import Fraction
 import logging
 
 from artiq.language import core as core_language
+from artiq.language import units
 from artiq.coredevice.runtime import Environment
 from artiq.coredevice import runtime_exceptions
 
@@ -23,6 +24,7 @@ class _H2DMsgType(Enum):
     LOAD_OBJECT = 2
     RUN_KERNEL = 3
     SET_BAUD_RATE = 4
+    SWITCH_CLOCK = 5
 
 
 class _D2HMsgType(Enum):
@@ -37,6 +39,8 @@ class _D2HMsgType(Enum):
     KERNEL_EXCEPTION = 9
     KERNEL_STARTUP_FAILED = 10
     RPC_REQUEST = 11
+    CLOCK_SWITCH_COMPLETED = 12
+    CLOCK_SWITCH_FAILED = 13
 
 
 def _write_exactly(f, data):
@@ -135,12 +139,21 @@ class Comm:
             runtime_id += chr(reply)
         if runtime_id != "AROR":
             raise UnsupportedDevice("Unsupported runtime ID: "+runtime_id)
-        (ref_freq_i, ref_freq_fn, ref_freq_fd) = struct.unpack(
+        ref_freq_i, ref_freq_fn, ref_freq_fd = struct.unpack(
             ">lBB", _read_exactly(self.port, 6))
-        ref_period = 1/(ref_freq_i + Fraction(ref_freq_fn, ref_freq_fd))
+        ref_freq = (ref_freq_i + Fraction(ref_freq_fn, ref_freq_fd))*units.Hz
+        ref_period = 1/ref_freq
         logger.debug("environment ref_period: {}".format(ref_period))
         return Environment(ref_period)
 
+    def switch_clock(self, external):
+        _write_exactly(self.port, struct.pack(
+            ">lbb", 0x5a5a5a5a, _H2DMsgType.SWITCH_CLOCK.value,
+            int(external)))
+        msg = self._get_device_msg()
+        if msg != _D2HMsgType.CLOCK_SWITCH_COMPLETED:
+            raise IOError("Incorrect reply from device: "+str(msg))
+
     def load(self, kcode):
         _write_exactly(self.port, struct.pack(
             ">lblL",

artiq/coredevice/core.py

@@ -42,13 +42,20 @@ def _no_debug_unparse(label, node):
 
 
 class Core:
-    def __init__(self, comm, runtime_env=None):
+    def __init__(self, comm, external_clock=None, runtime_env=None):
         if runtime_env is None:
             runtime_env = comm.get_runtime_env()
         self.runtime_env = runtime_env
         self.comm = comm
         self.core = self
 
+        if external_clock is None:
+            self.ref_period = self.runtime_env.internal_ref_period
+            self.comm.switch_clock(False)
+        else:
+            self.ref_period = external_clock
+            self.comm.switch_clock(True)
+
     def transform_stack(self, func_def, rpc_map, exception_map,
                         debug_unparse=_no_debug_unparse):
         lower_units(func_def, rpc_map)
@@ -57,7 +64,7 @@ class Core:
         remove_inter_assigns(func_def)
         debug_unparse("remove_inter_assigns_1", func_def)
 
-        quantize_time(func_def, self.runtime_env.ref_period)
+        quantize_time(func_def, self.ref_period.amount)
         debug_unparse("quantize_time", func_def)
 
         fold_constants(func_def)
@@ -69,7 +76,7 @@ class Core:
         interleave(func_def)
         debug_unparse("interleave", func_def)
 
-        lower_time(func_def, self.runtime_env.initial_time)
+        lower_time(func_def, self.runtime_env.warmup_time/self.ref_period)
         debug_unparse("lower_time", func_def)
 
         remove_inter_assigns(func_def)

artiq/coredevice/runtime.py

@@ -141,11 +141,11 @@ def _debug_dump_obj(obj):
 
 
 class Environment(LinkInterface):
-    def __init__(self, ref_period):
+    def __init__(self, internal_ref_period):
         self.cpu_type = "or1k"
-        self.ref_period = ref_period
+        self.internal_ref_period = internal_ref_period
         # allow 1ms for all initial DDS programming
-        self.initial_time = int(Fraction(1, 1000)/self.ref_period)
+        self.warmup_time = 1*units.ms
 
     def emit_object(self):
         tm = lt.TargetMachine.new(triple=self.cpu_type, cpu="generic")
@@ -155,4 +155,4 @@ class Environment(LinkInterface):
 
     def __repr__(self):
         return "<Environment {} {}>".format(self.cpu_type,
-                                            str(units.Hz/self.ref_period))
+                                            str(1/self.ref_period))

soc/runtime/comm_serial.c

@@ -11,6 +11,7 @@ enum {
     MSGTYPE_LOAD_OBJECT,
     MSGTYPE_RUN_KERNEL,
     MSGTYPE_SET_BAUD_RATE,
+    MSGTYPE_SWITCH_CLOCK,
 };
 
 /* device to host */
@@ -30,6 +31,9 @@ enum {
     MSGTYPE_KERNEL_STARTUP_FAILED,
 
     MSGTYPE_RPC_REQUEST,
+
+    MSGTYPE_CLOCK_SWITCH_COMPLETED,
+    MSGTYPE_CLOCK_SWITCH_FAILED,
 };
 
 static int receive_int(void)
@@ -169,6 +173,9 @@ void comm_serve(object_loader load_object, kernel_runner run_kernel)
             send_int(0x5a5a5a5a);
             uart_sync();
             uart_tuning_word_write(ftw);
+        } else if(msgtype == MSGTYPE_SWITCH_CLOCK) {
+            rtiocrg_clock_sel_write(receive_char());
+            send_char(MSGTYPE_CLOCK_SWITCH_COMPLETED);
         } else
             send_char(MSGTYPE_MESSAGE_UNRECOGNIZED);
     }