Method and apparatus for high-speed efficient bi-directional communication between multiple processor over a common bus

An apparatus comprising:

• a. shared resource;
• b. a plurality of users coupled to said shared resource wherein said plurality of users share the shared resource;
• a plurality of resource request lines being provided by said plurality of users wherein each of said plurality of users provides at least one of said plurality of resource request lines;
• each of the plurality of users providing a plurality of information bits on corresponding ones of the plurality of resource request lines when the user desires access to said shared resource;
• the information bits having encoded therein the urgency of a corresponding one of the shared resource requests;
• and
• c. a priority controller coupled to the plurality of resource request lines for granting priority to one of said plurality of users based upon the information bits received from the plurality of users.

An apparatus comprising:

• a. a shared resource;
• b. a plurality of users coupled to said shared resource wherein said plurality of users share said shared resource;
• a plurality of resource request lines being provided by said plurality of users wherein each of said plurality of users provides at least one of the plurality of resource request lines;
• each of the plurality of users asserting the at least one of the plurality of resource request lines when the user desires access to said shared resource;
• a plurality of priority input lines being provided to said plurality of users, each of said plurality of users being provided at least one of the plurality of priority input lines;
• and
• c. a priority controller coupled to the plurality of resource request lines and further coupled to the plurality of priority input lines for granting priority to one of said plurality of users;
• said priority controller combining predetermined ones of the plurality of resource request lines to form a resource request address, said priority controller providing said resource request address to a look-up table wherein said look-up table is programmed to provide a predefined priority signal to each of the plurality of priority inputs lines, for each combination of predetermined ones of the plurality of resource request lines, said look-up table being reprogrammable if another predefined priority signal is desired, for a same said resource request address.

A method of granting access to a shared resource wherein the shared resource is accessed by a plurality of users, comprising the steps of:

• a. providing a plurality of resource request signals wherein each of the plurality of resource request signals is provided by one of the plurality of users;
• the plurality of resource request signals indicating that a corresponding one of the plurality of users desires access to the shared resource;
• b. providing a look-up table wherein the look-up table has a resource request address input and a plurality of address locations;
• c. loading each of said plurality of address locations of said look-up table with a plurality of predefined priority signals;
• d. combining predetermined ones of the plurality of resource request signals provided in step (a) to form said resource request address, and providing said resource request address to said look-up table wherein said look-up table provides a predefined priority signal to each of a plurality of priority response signals wherein each of said plurality of priority response signals is coupled to selected one(s) of the plurality of users;
• and
• e. repeating steps (c)-(d) if another predefined priority signal located at said resource request address is desired.

A method of granting access to a shared resource wherein the shared resource is accessed by a plurality of users, comprising the steps of:

• a. providing a plurality of resource request signals wherein each of the plurality of resource request signals is provided by one of the plurality of users and wherein each of the plurality of resource request signals has a plurality of information bits;
• the plurality of resource request signals indicating that a corresponding one of the plurality of users desires access to the shared resource and the plurality of information bits of each of the plurality request signals indicating the urgency of the corresponding one of the plurality of users access to the shared resource;
• and
• b. combining predetermined ones of the plurality of resource request signals provided in step (a) to form a resource request address, including the plurality of information bits of each of the plurality of resource request signals, and providing said resource request address to a look-up table wherein said look-up table provides a predefined priority signal to each of a plurality of priority response signals, wherein each of said plurality of priority response signals is coupled to selected one(s) of the plurality of users.

A method of granting access to a shared resource wherein the shared resource is accessed by a plurality of users, each of the plurality of users having a corresponding priority input for granting priority to the corresponding user, comprising the steps of:

• a. providing a plurality of resource request signals wherein each of the plurality of resource request signals is provided by a corresponding one of the plurality of users indicating that the corresponding user desires access to the shared resource;
• b. providing a look-up table wherein the look-up table has an address input and a plurality of address locations;
• c. loading each of said plurality of address locations of said look-up table with a plurality of predetermined values;
• d. concatenating said plurality of resource request signals provided in step (a) thereby forming a resource request bus address;
• coupling the resource request bus address to the address input of the look-up table thereby selecting one of the plurality of address locations in the look-up table;
• e. providing a corresponding one of the plurality of predetermined values located at the selected address location of the look-up table to a corresponding one of the priority inputs of the plurality of users thereby granting priority to one of the plurality of users to use the shared resource;
• and
• f. repeating steps (c)-(e) if another corresponding one of the plurality of predetermined values located at the selected address location of the look-up table is desired.