System for reading dynamically changing data supporting partial reads of storage locations

For a host data processing system, a peripheral device comprising:

• a memory including a plurality of storage locations having addresses, at least one of the plurality of storage locations including a plurality of sections;
• means, coupled with the memory, for supplying data to the plurality of storage locations independent of the host data processing system;
• a host interface for reading the data in the plurality of storage locations, the host interface including:
• a read store, coupled to the memory and responsive to an address of one of the plurality of storage locations and an update signal, for storing data from the plurality of sections of the addressed storage location;
• addressing means for supplying addresses indicating selected storage locations and section enable signals indicating selected ones of the plurality of sections of addressed storage locations;
• means, coupled with the read store and the addressing means, for providing access to data in the read store to the host data processing, the provided data being from the selected ones of plurality of sections indicated by the section enable signals;
• and
• means for generating the update signal in response to the addresses and section enable signals so that the read store is not changed between sequential reads by the host data processing system to different sections of the same storage location, wherein the sequential reads being sequential in time and including a first read and a second read, the second read occurring after the first read and occurring without an intervening read existing between the first read and the second read;
• wherein the means for generating an update signal includes:
• means, responsive to the addresses, for detecting a sequence of at least two sequential reads by the host data processing system to the same storage location;
• and
• means, responsive to sequential reads by the host data processing system and section enable signals, for controlling the update signal so that the read store is not updated when the second read accesses a different section of the storage location than the first read, and the read store is updated when the second read accesses the same storage location as is accessed by the first read.