| US 7,508,836 B2 | ||
| Data processing apparatus and method for handling transactions | ||
| Satoshi Nakajima, Cambridge (United Kingdom) | ||
| Assigned to ARM Limited, Cambridge (United Kingdom) | ||
| Filed on Dec. 01, 2004, as Appl. No. 11/504. | ||
| Prior Publication US 2006/0114921 A1, Jun. 01, 2006 | ||
| Int. Cl. H04L 12/28 (2006.01); H04J 3/16 (2006.01) | ||
| U.S. Cl. 370—412 [370/465] | 19 Claims |
| 1. A data processing apparatus for handling transactions issued to a slave device from a master device, each transaction involving
the transfer of one or more data packets between the master device and the slave device, the data processing apparatus comprising:
a buffer storage operable to buffer the data packets of one or more transactions during transfer of those data packets between
the master and slave devices;
buffer control logic operable to control the operation of the buffer storage;
in a normal mode of operation the buffer control logic being operable to cause the buffer storage to operate as a FIFO storage
for buffering the data packets so as to maintain the temporal order of those data packets;
upon receipt of a high priority transaction, the buffer control logic being operable to cause the buffer storage to operate
in an alternative mode of operation in which an allocated portion of the buffer storage is reserved for buffering data packets
associated with that high priority transaction, whilst a remaining portion of the buffer storage is retained for buffering
of the data packets of other transactions;
whereby when the buffer storage is operating in the alternative mode of operation data packets in the allocated portion may
be output from the buffer storage out of temporal order with respect to data packets in the remaining portion.
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