Method for Performing Memory Diagnostics Using a Programmable Diagnostic Memory Module

• US 20090049341A1
• 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 7,730,369 B2
• Time in Patent Office: Days
• US Class Current: 714/39
• CPC Class Codes: G06F 11/24 Marginal checking or other specified testing methods not covered by G06F11/26, e.g. race tests

Abstract

A method for performing memory diagnostics using 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 method for testing a memory subsystem, comprising:

inserting a diagnostic memory module in the memory subsystem in place of an ordinary memory module by connecting the diagnostic memory module via memory module interface terminals to the memory subsystem; and

communicating with the diagnostic memory module to transfer diagnostic information between the diagnostic memory module and an external diagnostic system.

2. The method of claim 1, further comprising providing equivalent storage as would be otherwise provided by the ordinary memory module.

3. The method of claim 1, wherein the communicating transfers program instructions of a diagnostic program from the external diagnostic system to the diagnostic memory module, and further comprising executing the diagnostic program within the diagnostic memory module.

4. The method of claim 3, wherein the executing the diagnostic program comprises:

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

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 method of claim 1, wherein the communicating transfers a command to alter a loading of the diagnostic memory module at the memory module interface terminals.

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

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

8. The method of claim 1, wherein the communicating transfers a command to alter a drive strength of output signals provided from the diagnostic memory module at the memory module interface terminals.

9. The method of claim 1, wherein the communicating transfers a command to alter a timing relationship between address signals and data signals within the diagnostic memory module.

10. The method of claim 1, wherein the communicating communicates a command to the diagnostic memory module to emulate a particular module type of a plurality of memory module types, and wherein the method further comprises emulating the particular module type in response to receiving the command.

11. A method for testing a memory subsystem, comprising:

inserting a diagnostic memory module in the memory subsystem in place of an ordinary memory module by connecting the diagnostic memory module via memory module interface terminals to the memory subsystem;

communicating with the diagnostic memory module to transfer diagnostic information between the diagnostic memory module and an external diagnostic system, wherein said diagnostic information includes program instructions of a diagnostic program transferred from the external diagnostic system to the diagnostic memory module; and

executing the diagnostic program within the diagnostic memory module to store a stream of data corresponding to memory write operations received at the memory module interface terminals of the diagnostic memory module, alter the stream of data to generate an altered stream for simulating an error condition, and respond to memory read operations received at the memory module interface terminals by providing the altered stream at the memory module interface terminals.

12. The method of claim 11, wherein the communicating transfers a command to alter a loading of the diagnostic memory module at the memory module interface terminals.

13. The method of claim 11, wherein the communicating communicates a command to the diagnostic memory module to manipulate a signal on at least one of the memory module interface terminals in an analog domain to simulate noise, and wherein the diagnostic memory module manipulates the signal in response to receiving the command.

14. The method of claim 13, wherein the at least one memory module interface terminal is a power supply terminal of the memory subsystem.

15. The method of claim 13, wherein the diagnostic memory module manipulates the signal by providing values to an analog-to-digital converter to generate a simulated noise waveform.

16. The method of claim 11, wherein the communicating transfers a command to alter a drive strength of output signals provided from the diagnostic memory module at the memory module interface terminals.

17. The method of claim 11, wherein the communicating transfers a command to alter a timing relationship between address signals and data signals within the diagnostic memory module.

18. The method of claim 11, wherein the communicating communicates a command to the diagnostic memory module to emulate a particular module type of a plurality of memory module types, and wherein the method further comprises emulating the particular module type in response to receiving the command.

19. The method of claim 18, wherein the command specifies emulation of one of at least a set of types including DDR and DDR2 memory types.

20. A method for testing a memory subsystem, comprising:

inserting a diagnostic memory module in the memory subsystem in place of an ordinary memory module by connecting the diagnostic memory module via memory module interface terminals to the memory subsystem;

communicating with the diagnostic memory module to transfer diagnostic information between the diagnostic memory module and an external diagnostic system, wherein said diagnostic information includes program instructions of a diagnostic program transferred from the external diagnostic system to the diagnostic memory module;

executing the diagnostic program within the diagnostic memory module to store a stream of data corresponding to memory write operations received at the memory module interface terminals of the diagnostic memory module, alter the stream of data to generate an altered stream for simulating an error condition, and respond to memory read operations received at the memory module interface terminals by providing the altered stream at the memory module interface terminals;

sending a first command from the external diagnostic system to the diagnostic memory module to alter a loading of the diagnostic memory module at the memory module interface terminals;

sending a second command from the external diagnostic system to the diagnostic memory module to manipulate a signal on at least one of the memory module interface terminals in an analog domain to simulate noise, and wherein the diagnostic memory module manipulates the signal in response to receiving the command;

sending a third command from the external diagnostic system to the diagnostic memory module to alter a drive strength of output signals provided from the diagnostic memory module at the memory module interface terminals; and

sending a fourth command from the external diagnostic system to the diagnostic memory module to alter a timing relationship between address signals and data signals within the diagnostic memory module.