Changes between Initial Version and Version 1 of DsxTaskModel

Timestamp:

Aug 21, 2006, 4:13:32 PM (18 years ago)

Author:

Nicolas Pouillon

Comment:

--

DsxTaskModel

@@ +1 @@
+= Task models =
+
+A task model is a definition of an instanciable task, ie
+ * a name
+ * a list of ports accepting resources from different [wiki:DsxResource resource types]
+ * a list of available implementations
+
+= Task implementations =
+
+== Software Task ==
+
+A software task implementation is defined by:
+ * a function to call
+ * a list of C source files (even if some files are shared between tasks, you must redeclare them in each using task implementation definition)
+
+{{{
+tg = TaskModel(
+        'tg',
+        outfifos = ['output'],
+        impl = [ SwTask( 'tg',
+                         stack_size = 4096,
+                         sources = [ 'src/tg_posix.c' ] )
+               ] )
+}}}
+
+== Hardware Task ==
+
+An hardware implementation is in fact a corpocessor (which must be implemented in simulator/synthesis context and declared in DSX) doing the same thing as the task.
+
+The following restrictions apply:
+ * Task must only use MwMr fifos for data exchange
+ * Task must not be RealTime
+
+Declaration consists of:
+ * Coprocessor reference
+ * Optional coprocessor arguments
+
+{{{
+tg = TaskModel(
+        'tg',
+        outfifos = ['output'],
+        impl = [ SwTask( 'tg',
+                         stack_size = 4096,
+                         sources = [ 'src/tg_posix.c' ] )
+                 HwTask( Tg, filename = 'plan.jpg' )
+               ] )
+}}}
+
+== Virtual Task ==
+
+If a task follows constraints for having an hardware implementation, it may be virtually implemented in hardware, which means it will be run in simulator's context as if it were a coprocessor, actually using C implementation.
+
+This kind if virtualization is only available for SystemC simulation (ie not VHDL), and you must have defined a software implementation.
+If your task has a Virtual() declaration and an HwTask at the same time, the implementation chosen by DSX for simulation purposes will be unpredictable, you should avoid such situations.
+
+{{{
+idct = TaskModel(
+        'idct',
+        infifos = [ 'input' ],
+        outfifos = [ 'output' ],
+        impl = [ SwTask( 'idct',
+                         stack_size = 1024,
+                         sources = [ 'src/idct.c' ] ),
+                 Virtual()
+               ] )
+}}}
+
+== Task Synthesis ==
+
+Using Ugh, a task may be synthetized, this is not supported at this time.