Programmable Diagnostic Memory Module

• US 20090049339A1
• Filed: 08/17/2007
• Published: 02/19/2009
• Est. Priority Date: 08/17/2007
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Dreps, Daniel Mark, Mutnury, Bhyrav M., Pham, Nam H., Cases, Moises, De Araujo, Daniel N.
• Granted Patent: US 7,739,562 B2
• Time in Patent Office: Days
• US Class Current: 714/29
• CPC Class Codes: G06F 11/2733 Test interface between tester and unit under test
• CPC Class Codes: G11C 2029/5602 Interface to device under test
• CPC Class Codes: G11C 29/02 Detection or location of defective auxiliary circuits, e.g. defective refresh counters
• CPC Class Codes: G11C 29/022 in I/O circuitry
• CPC Class Codes: G11C 29/16 using microprogrammed units, e.g. state machines
• CPC Class Codes: G11C 29/56 External testing equipment for static stores, e.g. automatic test equipment [ATE]; Interfaces therefor
• CPC Class Codes: G11C 5/04 Supports for storage elements , e.g. memory modules; Mounting or fixing of storage elements on such supports

Abstract

A programmable diagnostic memory module provides enhanced testability of memory controller and memory subsystem design. The programmable diagnostic memory module includes an interface for communicating with an external diagnostic system, and the interface is used to transfer commands to the memory module to alter various behaviors of the memory module. The altered behaviors may be changing data streams that are written to the memory module to simulate errors, altering the timing and/or loading of the memory module signals, downloading programs for execution by a processor core within the memory module, changing driver strengths of output signals of the memory module, and manipulating in an analog domain, signals at terminals of the memory module such as injecting noise on power supply connections to the memory module. The memory module may emulate multiple selectable memory module types, and may include a complete storage array to provide standard memory module operation.

Claims

1. A diagnostic memory module, comprising:

memory module interface terminals for connecting the diagnostic memory module in place of an ordinary memory module in a memory subsystem;

a storage for storing a diagnostic program;

a processing unit for executing the diagnostic program; and

an interface for communicating between the processing unit and an external diagnostic system.

2. The diagnostic memory module of claim 1, further comprising a plurality of memory devices for providing equivalent storage as would be otherwise provided by the ordinary memory module.

3. The diagnostic memory module of claim 1, wherein the interface transfers program instructions of the diagnostic program from the external diagnostic system.

4. The diagnostic memory module of claim 1, wherein the diagnostic program comprises program instructions for:

storing a stream of data corresponding to memory write operations received at the memory module interface terminals;

altering the stream of data to generate an altered stream for simulating an error condition; and

responding to memory read operations received at the memory module interface terminals by providing the altered stream at the memory module interface terminals.

5. The diagnostic memory module of claim 1, further comprising a programmable loading circuit for altering an electrical load of one of more of the memory module interface terminals, whereby the behavior of the memory subsystem is altered.

6. The diagnostic memory module of claim 1, wherein the diagnostic memory module includes a circuit for manipulating a signal on at least one of the memory module interface terminals in an analog domain to simulate noise, wherein the interface receives a command to manipulate the signal, and wherein the circuit manipulates the signal in response to receiving the command.

7. The diagnostic memory module of claim 6, wherein the at least one memory module interface terminal is a power supply terminal.

8. The diagnostic memory module of claim 1, wherein an output driver of the diagnostic memory module has a programmable drive strength, wherein the interface receives a command to alter a drive strength of an output signal provided from the diagnostic memory module on at least one of the memory module interface terminals, and wherein the processing unit sets the programmable drive strength of the output driver in response to receiving the command.

9. The diagnostic memory module of claim 1, further comprising a timing offset circuit for adjusting a timing relationship between address signals and data signals within the diagnostic memory module, and wherein the interface receives a command to adjust the timing relationship between the address signals and the data signals, and wherein the processing unit programs the timing offset circuit to adjust the timing relationship in response to receiving the command.

10. The diagnostic memory module of claim 1, wherein the interface receives a command to emulate a particular module type of a plurality of memory module types, and wherein the processing unit sets the particular module type as an emulation type in response to receiving the command.

11. The diagnostic memory module of claim 1, further comprising at least one test point for probing signals within the diagnostic memory module.

12. A test workstation computer system, comprising a processor for executing workstation program instructions, a memory for storing the workstation program instructions, and an interface for communicating with a diagnostic memory module inserted in a target memory subsystem, wherein the workstation program instructions comprise program instructions for communicating with the diagnostic memory module to transfer diagnostic information between the diagnostic memory module and the test workstation computer system.

13. The test workstation computer system of claim 12, wherein the workstation program instructions for communicating transfer program instructions of a diagnostic program for execution by a diagnostic memory module processor core within the diagnostic memory module, from the test workstation computer system to the diagnostic memory module.

14. The test workstation computer system of claim 12, wherein the diagnostic program comprises program instructions for manipulating a stream of data written to the diagnostic memory module to produce an altered stream of data simulating an error condition, and providing the altered stream of data in response to a memory read operation received by the diagnostic memory module.

15. The test workstation computer system of claim 12, wherein the workstation program instructions for communicating communicate a command to program a programmable loading circuit for altering an electrical load of the diagnostic memory module in the target memory subsystem, whereby the behavior of the target memory subsystem is altered.

16. The test workstation computer system of claim 12, wherein the diagnostic memory module includes a circuit for manipulating signals within the target memory subsystem in an analog domain to simulate noise, wherein the workstation program instructions for communicating communicate a command to activate the circuit for manipulating signals, whereby the behavior of the target memory subsystem is altered.

17. The test workstation computer system of claim 12, wherein the diagnostic memory module includes an output driver having a programmable drive strength, wherein the workstation program instructions for communicating communicate a command to alter the drive strength.

18. The test workstation computer system of claim 12, wherein the diagnostic memory module further includes a timing offset circuit for adjusting a timing relationship between address signals and data signals within the diagnostic memory module, and wherein program instructions for communicating communicate a command to adjust the timing relationship between the address signals and the data signals.

19. A computer program product, comprising computer-readable storage media encoding workstation program instructions for execution by a test workstation computer system connected via an interface a diagnostic memory module inserted in a target memory subsystem, wherein the workstation program instructions comprise program instructions for communicating with a diagnostic memory module to transfer diagnostic information between the diagnostic memory module and the test workstation computer system.

20. The computer program product of claim 19, wherein the workstation program instructions for communicating transfer program instructions of a diagnostic program for execution by a diagnostic memory module processor core within the diagnostic memory module, from the test workstation computer system to the diagnostic memory module.

21. The computer program product of claim 20, wherein the diagnostic program comprises program instructions for manipulating a stream of data written to the diagnostic memory module to produce an altered stream of data simulating an error condition, and providing the altered stream of data in response to a memory read operation received by the diagnostic memory module.

22. The computer program product of claim 19, wherein the workstation program instructions for communicating communicate a command to program a programmable loading circuit for altering an electrical load of the diagnostic memory module in the target memory subsystem, whereby the behavior of the target memory subsystem is altered.

23. The computer program product of claim 19, wherein the diagnostic memory module includes a circuit for manipulating signals within the target memory subsystem in an analog domain to simulate noise, wherein the workstation program instructions for communicating communicate a command to activate the circuit for manipulating signals, whereby the behavior of the target memory subsystem is altered.

24. The computer program product of claim 19, wherein the diagnostic memory module includes an output driver having a programmable drive strength, wherein the workstation program instructions for communicating communicate a command to alter the drive strength.

25. The computer program product of claim 19, wherein the diagnostic memory module further includes a timing offset circuit for adjusting a timing relationship between address signals and data signals within the diagnostic memory module, and wherein program instructions for communicating communicate a command to adjust the timing relationship between the address signals and the data signals.

26. A programmable interactive diagnostic memory module, comprising:

memory module interface terminals for connecting the diagnostic memory module in place of an ordinary memory module in a memory subsystem;

a plurality of memory devices for providing equivalent storage as would be otherwise provided by the ordinary memory module;

a storage for storing a diagnostic program, wherein the diagnostic program includes program instructions for storing a stream of data corresponding to memory write operations received at the memory module interface terminals, altering the stream of data to generate an altered stream for simulating an error condition, and

responding to memory read operations received at the memory module interface terminals by providing the altered stream at the memory module interface terminals;

a processing unit for executing the diagnostic program;

an interface for communicating between the processing unit and an external diagnostic system, wherein the interface transfers program instructions of the diagnostic program from the external diagnostic system;

a programmable loading circuit for altering an electrical load of one of more of the memory module interface terminals, whereby the behavior of the memory subsystem is altered;

a circuit for manipulating a signal on at least one of the memory module interface terminals in an analog domain to simulate noise, wherein the interface receives a command to manipulate the signal, and wherein the circuit manipulates the signal in response to receiving the command;

an output driver having a programmable drive strength, wherein the interface receives a command to alter a drive strength of an output signal provided from the diagnostic memory module on at least one of the memory module interface terminals, and wherein the processing unit sets the programmable drive strength of the output driver in response to receiving the command;

a timing offset circuit for adjusting a timing relationship between address signals and data signals within the diagnostic memory module, and wherein the interface receives a command to adjust the timing relationship between the address signals and the data signals, and wherein the processing unit programs the timing offset circuit to adjust the timing relationship in response to receiving the command; and

at least one test point for probing signals within the diagnostic memory module.