Network on chip

• US 8,392,664 B2
• Filed: 05/09/2008
• Issued: 03/05/2013
• Est. Priority Date: 05/09/2008
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Comparan, Miguel, Hoover, Russell D., Mejdrich, Eric O.
• Primary Examiner(s): TSAI, SHENG JEN
• Application Number:
  US12/118,017
• Publication Number:
  US 20090282197A1
• Time in Patent Office: 1,761 Days
• Field of Search: 711/142, 711/E12.024, 711/E12.032
• US Class Current: 711/142
• CPC Class Codes: G06F 12/126 with special data handling, e.g. priority of data or instructions, handling errors or pinning

Abstract

A network on chip (‘NOC’) that includes integrated processor (‘IP’) blocks, routers, memory communications controllers, and network interface controllers; each IP block adapted to a router through a memory communications controller and a network interface controller; and at least one IP block also including a computer processor and an L1, write-through data cache comprising high speed local memory on the IP block, the cache controlled by a cache controller having a cache line replacement policy, the cache controller configured to lock segments of the cache, the computer processor configured to store thread-private data in main memory off the IP block, the computer processor further configured to store thread-private data on a segment of the L1 data cache, the segment locked against replacement upon cache misses under the cache controller'"'"'s replacement policy, the segment further locked against write-through to main memory.

Claims

1. A network on chip (‘

NOC’

) comprising;

integrated processor (‘

IP’

) blocks, routers, memory communications controllers, and network interface controllers;

each IP block adapted to a router through a memory communications controller and a network interface controller;

each memory communications controller controlling communications between an IP block and memory;

each network interface controller controlling inter-IP block communications through routers; and

at least one IP block further comprising a computer processor and an L1, write-through data cache comprising high speed local memory on the IP block, the cache controlled by a cache controller having a cache line replacement policy, the cache controller configured to lock segments of the cache, the computer processor configured to store thread-private data in main memory off the IP block, the computer processor further configured to store thread-private data on a segment of the L1 data cache, the segment locked against replacement upon cache misses under the cache controller'"'"'s replacement policy, the segment further locked against write-through to main memory, wherein the cache controller configured to lock segments of the cache further comprises the cache controller configured to load and lock a cache line in a segment upon the first load of the cache line by a thread owning private data and based on the thread'"'"'s private data.

2. The NOC of claim 1 wherein:

each page of memory is characterized by an attribute indicating whether the page contains thread-private data; and

the cache controller is configured to lock a cache line upon a first load of the cache line from a page of memory containing thread-private data.

3. The NOC of claim 1 wherein the cache controller is further configured to release the lock on a segment of the cache upon behest of a thread that loaded thread-private data into the segment.

4. The NOC of claim 1 wherein the computer processor further configured to store thread-private data on a segment of the L1 data cache further comprises the computer processor configured to store the thread-private data on at least one way of an N-way set-associative L1 data cache, where the value of N is at least two.

5. The NOC of claim 1 wherein the memory communications controller comprises:

a plurality of memory communications execution engines, each memory communications execution engine enabled to execute a complete memory communications instruction separately and in parallel with other memory communications execution engines; and

bidirectional memory communications instruction flow between the network and the IP block.

6. The NOC of claim 1 wherein memory comprises:

off-chip main ram;

memory connected directly to an IP block through a memory communications controller;

on-chip memory enabled as an IP block; and

on-chip caches.

7. The NOC of claim 1 wherein each IP block comprises a reusable unit of synchronous or asynchronous logic design used as a building block for data processing within the NOC.

8. The NOC of claim 1 wherein each router comprises:

two or more virtual communications channels, each virtual communications channel characterized by a communication type.

9. The NOC of claim 1 wherein each network interface controller is enabled to:

convert communications instructions from command format to network packet format; and

implement virtual channels on the network, characterizing network packets by type.

10. A method of data processing with a network on chip (‘

NOC’

), the NOC comprising IP blocks, routers, memory communications controllers, and network interface controllers, each IP block adapted to a router through a memory communications controller and a network interface controller,

at least one IP block further comprising a computer processor and an L1, write-through data cache comprising high speed local memory on the IP block, the computer processor configured to store thread-private data in main memory off the IP block, the cache controlled by a cache controller having a cache line replacement policy,

the method comprising;

controlling by each memory communications controller communications between an IP block and memory, controlling by each network interface controller inter-IP block communications through routers,

locking, by the cache controller, a segment of the L1 data cache, the segment locked against replacement upon cache misses under the cache controller'"'"'s replacement policy, the segment further locked against write-through to main memory;

loading and locking a cache line in the segment upon the first load of the cache line by a thread owning private data and based on the thread'"'"'s private data; and

storing, by the computer processor, the thread-private data on the segment of the L1 data cache.

11. The method of claim 10 wherein each page of memory is characterized by an attribute indicating whether the page contains thread-private data and locking, by the cache controller, a segment of the L1 data cache further comprises:

locking a cache line upon a first load of the cache line from a page of memory containing thread-private data.

12. The method of claim 10 further comprising releasing, by the cache controller, the lock on the segment of the cache upon behest of a thread that loaded thread-private data into the segment.

13. The method of claim 10 wherein storing, by the computer processor, the thread-private data on the segment of the L1 data cache further comprises storing the thread-private data on at least one way of an N-way set-associative L1 data cache, where the value of N is at least two.

14. The method of claim 10 wherein the memory communications controller comprises a plurality of memory communications execution engines and controlling communications between an IP block and memory further comprises:

executing by each memory communications execution engine a complete memory communications instruction separately and in parallel with other memory communications execution engines; and

executing a bidirectional flow of memory communications instructions between the network and the IP block.

15. The method of claim 10 wherein memory comprises:

off-chip main ram;

memory connected directly to an IP block through a memory communications controller;

on-chip memory enabled as an IP block; and

on-chip caches.

16. The method of claim 10 wherein each IP block comprises a reusable unit of synchronous or asynchronous logic design used as a building block for data processing within the NOC.

17. The method of claim 10 further comprising transmitting messages by each router through two or more virtual communications channels, each virtual communications channel characterized by a communication type.

18. The method of claim 10 wherein controlling inter-IP block communications further comprises:

converting by each network interface controller communications instructions from command format to network packet format; and

implementing by each network interface controller virtual channels on the network, characterizing network packets by type.