Bus recovery apparatus and method of recovery in a multi-master bus system

Claim 1

A bus recovery system for multi-master bus system, comprising: a plurality of bus masters selectively interfacing with a system bus, one of said bus masters being a default bus master; a plurality of counters corresponding to each of said plurality of bus masters, each of said counters containing a pre-determined time value corresponding to a maximum time each of said plurality of bus masters may be granted access to said bus; a bus arbiter for receiving requests from said plurality of bus masters for access to said bus, said arbiter granting access to one of said plurality of said bus masters and initiating counting by one of said plurality of counters corresponding to said one of said plurality of bus masters; a register for identifying and storing which one of said plurality of bus masters was currently accessing said bus when said pre-determined time value in said one of said plurality of counters has been exceeded by said one of said plurality of masters currently accessing said bus, said arbiter releasing ownership of said bus when said pre-determined time value in said counter has been exceeded by said one of said plurality of bus masters currently accessing said bus, and said arbiter granting access to said bus to said default bus master in response to said releasing ownership of said bus by the current bus master.

Claim 4

A method for bus recovery in a multi-master bus system having a plurality of bus masters and a plurality of counters corresponding to each of said plurality of bus masters, one of said bus masters being a default bus master, said method comprising: loading a pre-determined time value in each of said plurality of counters indicative of a maximum time each of said plurality of bus masters may be granted access to said bus; receiving requests from said plurality of bus masters for access to said system bus; granting access to one of said plurality of bus masters; counting the pre-determined time value in one of said plurality of counters corresponding to said one of said plurality of bus masters currently accessing said bus; identifying and storing in a register which one of said plurality of bus masters was currently accessing said bus when said predetermined time value in said one of said plurality of counters has been exceeded; releasing ownership of said bus when said pre-determined time value in said one of said plurality of counters has been exceeded by said one of said plurality of bus masters currently accessing said bus; and granting access to said bus to said default bus master in response to said releasing ownership of said bus by said one of said plurality of bus masters.

Claim 5

A method for bus recovery in a multi-master bus system having a plurality of bus masters and a plurality of counters corresponding to each of said plurality of bus masters, one of said bus masters being a default bus master, said method comprising: loading a pre-determined time value in each of said plurality of counters indicative of a maximum time each of said plurality of bus masters may be granted access to said bus; receiving requests from said plurality of bus masters for access to said system bus; granting access to one of said plurality of bus masters; counting the pre-determined time value in one of said plurality of counters corresponding to said one of said plurality of bus masters currently accessing said bus; identifying and storing in a register which one of said plurality of bus masters was currently accessing said bus when said predetermined time value in said one of said plurality of counters has been exceeded; releasing ownership of said bus when said pre-determined time value in said one of said plurality of counters has been exceeded by said one of said plurality of bus masters currently accessing said bus; and granting access to said bus to said default bus master in response to said releasing ownership of said bus by said one of said plurality of bus masters.