Changes between Version 65 and Version 66 of InterconnexionNetworks

Timestamp:

Apr 22, 2013, 12:29:55 AM (11 years ago)

Author:

alain

Comment:

--

InterconnexionNetworks

@@ -303 +303 @@
 || 1 ||   (10) ||       (15)        || (4) ||(2) ||0 ||
 
-== 7.  External Network ==
-
-TBD
-
+== 7. VCI initiators & targets on the external network ==
+
+The only targets on the external network are the physical memory bank (one target per cluster).
+The initiators are the memory cache (one initiator per cluster) and the I/O bridge (one extra initiator in the I/O cluster.
+As for the direct network, each VCI port is identified by three indexes :
+
+ * '''X_ID''' is the cluster X-coordinate in the 2D mesh.
+ * '''Y_ID''' is the cluster Y-coordinate in the 2D mexh. 
+ * '''L_ID''' is the local index inside the cluster. 
+
+X_ID, Y_ID and L_ID are coded on NX, NY, NL bits respectively.
+The local index is only used to discriminate the initiators. It is not used by the targets. 
+
+|| Initiator    ||L_ID||
+||              ||    ||
+|| memory cache || 0  ||
+|| I/O bridge   || 1  ||
+
+Here is the VCI encoding on the external network
+
+|| VCI Field              ||  width  ||
+||                        ||         ||
+||ADDRESS                 || 40 bits ||
+||WDATA , RDATA           || 64 bits ||
+||PLEN                    || 7  bits ||
+||SRCID, RSRCID           || 14 bits ||
+||TRDID, RTRDID           || 4  bits ||
+||PKTID, RPKTID           || 0  bits || 
+||RERROR                  || 1  bit  ||         
+
+The only supported transactions are READ and WRITE transactions. 
+Bursts are supported, but all addresses in a burst 
+Only should be in the same cache line (64 bytes).
+We don't transport the VCI BE field on the external network, as the byte operations are not supported.
+We don't transport the VCI PKTID field 
+
+== 8.  DSPIN packet encoding on the direct network ==
+
+The VCI command & response packets are translated (actually serialized) to DSPIN format by the VCI/DSPIN wrappers.  For both the DSPIN command packet and the response packet, the flit width is 65 bits. and the DSPIN response packet width is 33 bits. 
+The DSPIN interconnexion network uses only the following information to route the DSPIN packets to the proper destination:
+ * The EOP flag, defining the last flit of a DSPIN packet.
+ * The (NX+NY+NL) MSB bits of the first field are used to route the packet to the proper destination.
+
+
+=== 8.1 DSPIN Read Command packet format (65 bits) ===
+
+A single flit VCI Read Command packet is translated to a single flits DSPIN Read Command packet. 
+
+Flit 0 : 
+||EOP||----------------ADDRESS--------------------||PLEN||CMD||SRCID||TRDID||
+|| 1 ||                (38)                       || (7)||(1)|| (14)|| (4) ||
+
+=== 8.2 DSPIN write Command packet format (65 bits) ===
+
+A N flits VCI Write Command packet is translated to a (N+1) flits DSPIN Write Command packet.
+As a DATA flit contains 8 bytes
+
+Flit 0 :
+||EOP||----------------ADDRESS--------------------||PLEN||CMD||SRCID||TRDID||
+|| 0 ||                (38)                       || (7)||(1)|| (14)|| (4) || 
+
+Flit N :
+||EOP||----------------------------WDATA-----------------------------------||
+|| 1 ||                            (64)                                    ||
+
+=== 8.3 DSPIN Read Response packet format (65 bits) ===
+
+A N flits VCI Read Response packet is translated to a (N+1) flits DSPIN Read Response packet.
+
+Flit 0 :
+||EOP||RSRCID||------------ res ---------------------------||RERROR||RTRDID||
+|| 0 || (14) ||             (44)                           || (2)  || (4)  ||
+
+Flit N :
+||EOP||---------------------------RDATA------------------------------------||
+|| 1 ||                           (64)                                     ||
+
+=== 8.4 DSPIN Write Response packet format (65 bits) ===
+
+A single flit VCI Write Response packet is translated to a single flit DSPIN Write Response packet.
+
+Flit 0 :
+||EOP||RSRCID||------------ res ---------------------------||RERROR||RTRDID||
+|| 1 || (14) ||             (44)                           || (2)  || (4)  ||
+
+