Method and arrangement for data transmission between units on a bus system selectively transmitting data in one of a first and a second data transmission configurations

• US 6,032,178 A
• Filed: 01/12/1998
• Issued: 02/29/2000
• Est. Priority Date: 01/12/1998
• Status: Expired due to Term

• Current Assignee: Infineon Technologies AG
• Original Assignee: Siemens AG
• Inventors: Erdmann, Michael, Rohm, Peter, Bacigalupo, Tommaso
• Primary Examiner(s): An, Meng-Ai T.
• Assistant Examiner(s): EL HADY, NABIL M
• Application Number:
  US09/005,696
• Time in Patent Office: 778 Days
• Field of Search: 709/200, 709/208, 709/209, 709/227, 709/232, 709/245, 710/4, 710/11, 710/14, 710/20, 710/21, 710/33, 710/110, 710/129, 710/131
• US Class Current: 709/208
• CPC Class Codes: G06F 13/364 using independent requests or grants, e.g. using separated request and grant lines

Abstract

The invention relates to a method and an arrangement for operating a bus system having at least one master unit and at least one slave unit, having a bus and a bus control unit for the bus arbitration and for controlling the data transfer. The data transmission is split into a request data transfer and a response data transfer, and, in the time between the request data transfer and the response data transfer, the bus is cleared for the data transmissions of other master units in a first data transmission configuration, or the bus is blocked between the request data transfer and the response data transfer, in a second data transmission configuration and slave units. In the case of a response transfer, the master and slave are changed round.

Claims

1. A method of operating a bus system, wherein the bus system has at least one primary unit, at least one secondary unit, at least one bus control unit, and a bus between the at least one primary unit and the at least one secondary unit, the bus having at least one address bus, at least one data bus and at least one control line, the method which comprises:

defining a first data transmission configuration between the at least one primary unit and the at least one secondary unit, splitting a data transmission into a request data transfer and a response data transfer in the first data transmission configuration, and clearing the bus for data transmissions of other primary units and secondary units in a time between the request data transfer and the response data transfer;

defining a second data transmission configuration between the at least one primary unit and the at least one secondary unit, blocking the bus between the request data transfer and the response data transfer in the second data transmission configuration; and

controlling a data transmission between the at least one primary unit and the at least one secondary unit, addressed by the at least one primary unit, by selectively transmitting data in the first and second data transmission configurations.

2. The method according to claim 1, wherein the step of transmitting data in the request data transfer in the first data transmission configuration comprises:

addressing the at least one secondary unit, with the at least one primary unit allocated for bus access as a master; and

requesting, with the at least one primary unit, a data transfer from the addressed at least one secondary unit, and

wherein the step of transmitting data in the response data transfer in the first data transmission configuration comprises;

at least partially collecting the data set intended for the response data transfer by using the addressed secondary unit; and

sending the collected data set to the at least one primary unit having requested the data transfer, by using the at least one secondary unit as a master.

3. The method according to claim 1, wherein the at least one control line is one of a plurality of control lines, the method further comprises:

specifying with the at least one primary unit that the data transmission is carried out in the first data transmission configuration, by using a configuration signal on at least one of the control lines.

4. The method according to claim 1, wherein the at least one control line is one of a plurality of control lines, and wherein the method further comprises:

selectively rejecting a data transfer, specified by the at least one primary unit, with the at least one secondary unit, in one of the first data transmission configuration and the second data transmission configuration, by using a configuration signal on at least one of the control lines; and

performing the data transfer, with the at least one secondary unit, in at least one of the second and the first data transmission configuration.

5. The method according to claim 1, wherein the at least one control line is one of a plurality of control lines, and wherein the method further comprises:

enforcing a data transfer selectively in one of the data transmission configurations, by the at least one primary unit using a configuration signal on at least one of the control lines.

6. The method according to claim 1, wherein the at least one primary unit is one of a plurality of primary units, the method further comprises:

simultaneously carrying out a maximum of one data transmission with each of the primary units.

7. The method according to claim 1, wherein the at least one primary unit is one of a plurality of primary units, the method further comprises:

controlling the allocation of the bus to one of the primary units with the bus control unit.

8. The method according to claim 1, which further comprises:

transmitting data in the second data transmission configuration during wait states.

9. The method according to claim 1, which further comprises:

processing bus operations of an address cycle and a data cycle by using a pipelining method.

10. The method according to claim 1, wherein the at least one control line is one of a plurality of control lines, the method further comprises:

preventing a write access to a register of the at least one secondary unit involved in a data transmission when read access is occurring, by using a protection bit on at least one of the control lines.

11. The method according to claim 1, wherein the at least one control line is one of a plurality of control lines, the method further comprises:

specifying a data length transmitted, by using a control signal on at least one of the control lines.

12. The method according to claim 1, wherein the at least one control line is one of a plurality of control lines, the method further comprises:

specifying the mode in which the at least one primary unit accesses the bus, by using a control signal on at least one of the control lines.

13. The method according to claim 1, wherein the at least one control line is one of a plurality of control lines, the method further comprises:

acknowledging a data transmission by the at least one secondary unit using an acknowledge signal on at least one of the control lines.

14. The method according to claim 1, wherein the at least one control line is one of a plurality of control lines, the method further comprises:

selectively indicating whether data are available for processing and whether data are currently processed, by the at least one secondary unit using a status signal on at least one of the control lines.

15. The method according to claim 1, wherein the at least one control line is one of a plurality of control lines, the method further comprises:

selectively indicating whether any wait states are inserted and how many wait states are inserted, by the at least one secondary unit using a status signal on at least one of the control lines.

16. The method according to claim 1, wherein the at least one control line is one of a plurality of control lines, the method further comprises:

selectively indicating whether successive bus cycles have been carried out without interruption and whether any error states have occurred, by the at least one secondary unit using a status signal on at least one of the control lines.

17. The method according to claim 1, wherein the at least one control line is one of a plurality of control lines, the method further comprises:

aborting a data transmission after a predetermined time, by the bus control unit using an abort signal on at least one of the control lines.

18. The method according to claim 1, wherein the at least one primary unit is one of a plurality of primary units and the at least one control line is one of a plurality of control lines, the method further comprises:

specifying an allocation of the primary units to the bus, by the bus control unit using a request signal and a grant signal on at least one of the control lines.

19. A circuit arrangement for operating a bus system, comprising:

at least one primary unit;

at least one secondary unit;

a bus between said at least one primary unit and said at least one secondary unit having at least one address bus, at least one data bus and at least one control line;

at least one bus control unit controlling said bus and controlling a data transmission between said at least one primary unit, allocated to said bus, and said at least one secondary unit, addressed by said at least one primary unit, the data transmission being carried out selectively in one of a first data transmission configuration and a second data transmission configuration, the data transmission being split into a request data transfer and a response data transfer in the first data transmission configuration, and said bus being cleared for data transmissions of other primary units and secondary units in a time between the request data transfer and the response data transfer, said bus being blocked between the request data transfer and the response data transfer in the second data transmission configuration; and

a logic circuit in said at least one primary unit and said at least one secondary unit linked to the bus system, for requesting, rejecting, and selecting the data transmission selectively in one of the first and second data transmission configurations.

20. The circuit arrangement according to claim 19, including:

a timer for timing the data transmission in the first data transmission configuration provided in both of said at least one primary unit and said at least one secondary unit.

21. The circuit arrangement according to claim 19, including:

at least one buffer memory device in said at least one secondary unit.

22. The circuit arrangement according to claim 21, wherein said buffer memory device has a memory size at least large enough to deal with a data transfer at an optimum rate.

23. The circuit arrangement according to claim 19, including:

at least two primary units; and

a prioritizer for specifying the priority of said primary units accessing said bus, said prioritizer provided in said bus control unit.

24. The circuit arrangement according to claim 19, wherein said at least one primary unit is one of a plurality of primary units, said circuit arrangement including:

a master/slave interface provided in at least one of said primary units.

25. The circuit arrangement according to claim 19, including:

said bus operable to transmit addresses selectively in one of a non-multiplexed mode on said address bus, and in a multiplexed mode on said address bus and said data bus.

26. The circuit arrangement according to claim 19, including:

at least one central processing unit provided in said at least one primary unit.

27. The circuit arrangement according to claim 19, wherein said at least one primary unit is one of a plurality of primary units, said circuit arrangement including:

one of said primary units provided as a default master, said default master allocated to said bus if no other primary unit requests said bus.

28. In a microprocessor, a circuit arrangement for operating a bus system, comprising:

at least one primary unit;

at least one secondary unit;

a bus between said at least one primary unit and said at least one secondary unit having at least one address bus, at least one data bus and at least one control line;

at least one bus control unit controlling said bus and controlling a data transmission between said at least one primary unit, allocated to said bus, and said at least one secondary unit, addressed by said at least one primary unit, the data transmission being carried out selectively in one of a first data transmission configuration and a second data transmission configuration, the data transmission being split into a request data transfer and a response data transfer in the first data transmission configuration, and said bus being cleared for data transmissions of other primary units and secondary units in a time between the request data transfer and the response data transfer, said bus being blocked between the request data transfer and the response data transfer in the second data transmission configuration; and

a logic circuit in said at least one primary unit and said at least one secondary unit linked to the bus system, for requesting, rejecting, and selecting the data transmission selectively in one of the first and second data transmission configurations.

29. In a microcomputer, a circuit arrangement for operating a bus system, comprising:

at least one primary unit;

at least one secondary unit;

a bus between said at least one primary unit and said at least one secondary unit having at least one address bus, at least one data bus and at least one control line;

at least one bus control unit controlling said bus and controlling a data transmission between said at least one primary unit, allocated to said bus, and said at least one secondary unit, addressed by said at least one primary unit, the data transmission being carried out selectively in one of a first data transmission configuration and a second data transmission configuration, the data transmission being split into a request data transfer and a response data transfer in the first data transmission configuration, and said bus being cleared for data transmissions of other primary units and secondary units in a time between the request data transfer and the response data transfer, said bus being blocked between the request data transfer and the response data transfer in the second data transmission configuration; and

a logic circuit in said at least one primary unit and said at least one secondary unit linked to the bus system, for requesting, rejecting, and selecting the data transmission selectively in one of the first and second data transmission configurations.