Re-purposing byte enables as clock enables for power savings

Abstract

Systems, apparatuses, and methods for efficient data transfer in a computing system are disclosed. A source generates packets to send across a communication fabric (or fabric) to a destination. The source generates partition enable signals for the partitions of payload data. The source negates an enable signal for a particular partition when the source determines the packet type indicates the particular partition should have an associated asserted enable signal in the packet, but the source also determines the particular partition includes a particular data pattern. Routing components of the fabric disable clock signals to storage elements assigned to store the particular partition. The destination inserts the particular data pattern for the particular partition in the payload data.

What is claimed is: 
     
         1 . A computing system, comprising:
 a source comprising circuitry configured to generate a packet comprising:
 a plurality of partitions of a data payload; and 
 a plurality of enable signals, each associated with a partition of the plurality of partitions; 
   a destination; and   a routing component coupled to each of the source and the destination;   wherein the routing component comprises circuitry configured to:
 receive the packet from the source; and 
 disable a clock signal for each storage element of the routing component configured to store data of a given partition of the plurality of partitions, in response to determining the given partition has an associated enable signal in the packet that is negated. 
   
     
     
         2 . The computing system as recited in  claim 1 , wherein the routing component is further configured to convey to the destination:
 the negated enable signal; and   a previous value stored in each storage element assigned to store data of the given partition.   
     
     
         3 . The computing system as recited in  claim 1 , wherein the routing component is further configured to enable a clock signal for each storage element of the routing component assigned to store data of the given partition, in response to:
 determining the given partition has an associated asserted enable signal in the packet.   
     
     
         4 . The computing system as recited in  claim 1 , wherein the source is further configured to negate an enable signal for the given partition, in response to:
 determining a type of the packet indicates the given partition has an associated asserted enable signal in the packet; and   determining the given partition comprises a given data pattern.   
     
     
         5 . The computing system as recited in  claim 4 , wherein the type of the packet indicating the given partition has an associated asserted enable signal in the packet comprises a response type of packet. 
     
     
         6 . The computing system as recited in  claim 1 , wherein the destination is further configured to:
 receive the packet from the routing component; and   insert the given data pattern in the given partition of the packet, in response to:
 determining a type of the packet indicates the given partition has an associated asserted enable signal in the packet; and 
 determining the given partition has an associated negated enable signal in the packet. 
   
     
     
         7 . The computing system as recited in  claim 1 , wherein the routing component further comprises one of a switch and a repeater of a communication fabric between the source and the destination. 
     
     
         8 . The computing system as recited in  claim 1 , wherein the source comprises one or more of a central processing unit, a graphics processing unit and a multimedia engine. 
     
     
         9 . A method, comprising:
 generating, by a source, a packet comprising:
 a plurality of partitions of a data payload; and 
 a plurality of enable signals, each associated with a partition of the plurality of partitions; 
   processing, by a destination, the packet; and   receiving, by a routing component, the packet from the source;   disabling, by the routing component, a clock signal for each storage element of the routing component assigned to store data of a given partition of the plurality of partitions, in response to determining the given partition has an associated negated enable signal in the packet.   
     
     
         10 . The method as recited in  claim 9 , further comprising conveying to the destination:
 the negated enable signal; and   a previous value stored in each storage element assigned to store data of the given partition.   
     
     
         11 . The method as recited in  claim 9 , further comprising enabling a clock signal for each storage element of the routing component assigned to store data of the given partition, in response to:
 determining the given partition has an associated asserted enable signal in the packet.   
     
     
         12 . The method as recited in  claim 9 , further comprising negating an enable signal for the given partition, in response to:
 determining a type of the packet indicates the given partition has an associated asserted enable signal in the packet; and   determining the given partition comprises a given data pattern.   
     
     
         13 . The method as recited in  claim 12 , wherein the type of the packet indicating the given partition has an associated asserted enable signal in the packet comprises a cache victim type of packet. 
     
     
         14 . The method as recited in  claim 12 , wherein the type of the packet indicating the given partition has an associated asserted enable signal in the packet comprises a full size write type of packet. 
     
     
         15 . The method as recited in  claim 9 , further comprising:
 receiving, by the destination, the packet from the routing component; and   inserting, by the destination, the given data pattern in the given partition of the packet, in response to:
 determining a type of the packet indicates the given partition has an associated asserted enable signal in the packet; and 
 determining the given partition has an associated negated enable signal in the packet. 
   
     
     
         16 . The method as recited in  claim 9 , wherein the routing component comprises one of a switch and a repeater of a communication fabric between the source and the destination. 
     
     
         17 . An apparatus, comprising:
 a first interface configured to receive, from a source, a packet comprising:
 a plurality of partitions of a data payload; and 
 a plurality of enable signals, each associated with a partition of the plurality of partitions; 
   a second interface configured to convey the packet to a destination;   a plurality of storage elements; and   circuitry configured to:
 disable a clock signal for each storage element of the plurality of storage elements assigned to store data of a given partition of the plurality of partitions, in response to determining the given partition has an associated negated enable signal in the packet. 
   
     
     
         18 . The apparatus as recited in  claim 17 , wherein the circuitry is further configured to convey, via the second interface, to the destination:
 the negated enable signal; and   a previous value stored in each storage element assigned to store data of the given partition.   
     
     
         19 . The apparatus as recited in  claim 17 , wherein the circuitry is further configured to enable a clock signal for each storage element of the plurality of storage elements assigned to store data of the given partition, in response to:
 determining the given partition has an associated asserted enable signal in the packet.   
     
     
         20 . The apparatus as recited in  claim 17 , wherein the apparatus comprises a switch of a communication fabric between the source and the destination.