Choose one of the following topics to find out more about the Memory Expert Tool:
The Memory Expert Tool is designed to help you isolate problems in main memory, by providing address resolution and memory testing.
This tool provides five Main level pulldown menus: help, file, tools, REFRESH and EXIT.
The help pulldown menu accesses this help facility.
The file pulldown menu simply allows the user to exit.
The tools pulldown menu lets you select the Address Resolution or Memory Test functions.
The EXIT pulldown menu quits the tool.
There are three pulldown menus common to most levels: help, REFRESH and previous menu.
The help pulldown menu provides access to this help information.
The REFRESH pulldown menu redisplays the current screen.
The previous menu pulldown menu will return to the previous level pulldown menus.
These Pulldown Menus can be selected at the Memory Expert Tool main prompt:
The exit Pulldown menu is available at the main tool prompt. It is used to quit the expert tool.
The Address Resolution pulldown menu is available after using the tools pulldown menus. It is used to obtain details about a memory address.
When you invoke this command, you will be prompted for the address you would like resolved. The prompt will only allow you to enter valid addresses up to the highest address on the unit under test. Addresses are specified in hexadecimal notation.
The prompt also allows you to cancel the test or obtain help. If you hit OK, the address is resolved to provide information like this:
Memory Expert>ar -- Expert tool: Address Resolution for device MEMORY. --
Address to Resolve (hex): [0] 4f380
Address: 0x04f380 Page: 79 Page Status: BUSY (may be available later) Board: EXT0 0a/0b Physical Bank: 0 Logical Bank: 3
The address resolution was SUCCESSFUL.
Note that the information is for the byte at the address in question. For several systems, an address that is one byte different may resolve to a different board. The page number is given in decimal.
The Memory Test pulldown menu is available after using the tools pulldown menus. They are used to initiate a memory test.
When you enter this command, you will see a large dialog which allows you to specify the many memory test parameters.
The Write, Read, Compare buttons enable you to specify the type of test that is performed on each page. By default, each page is written, then read back, and the results compared.
Because of the Error Correction Code (ECC) circuitry, the comparison actually detects problems with the ECC rather than single-bit errors in RAM. The single-bit errors are detected later in the test, during its periodic probe of the syndrome registers of all memory controllers to report any errors that transpired during the test.
If desired, the test can be diluted to only read or only write memory.
By default, the test will range over every page in memory. You may specify any range, though of course out-of-range pages are disallowed, and the start page must be less than or equal to the end page. The range is inclusive, and may consist of one page only. However, if the page range is very tight, it can happen that none of the pages can be locked and tested. Further, low pages are often permanently reserved by the OS and are rarely testable.
When a page is obtainable for testing, a pattern is used to write to it and fill it with data.
The following patterns are available:
This pattern is a series of 3 patterns. When a page is obtained, it is first filled with the pattern All 0's. This is followed by All 1's, and then by All 0's again. While simpler tests can be selected, this is recommended as the default as the most basic test of memory.
This pattern is a series of all patterns. When a page is obtained, it is tested with every pattern in turn. This is the most comprehensive test, though it can be time consuming.
This pattern fills the entire page with a pattern that alternates every bit. The complement of this pattern is also available.
The walking one pattern looks like this:
0000000000000000000000000000000000000000000000000000000000000001 0000000000000000000000000000000000000000000000000000000000000010 0000000000000000000000000000000000000000000000000000000000000100 0000000000000000000000000000000000000000000000000000000000001000 etc...
In binary, from a field of 64 zero bits, one of the bits is set to one. The complement of this pattern, Walking Zero, is also available.
The walking zero pattern looks like this:
1111111111111111111111111111111111111111111111111111111111111110 1111111111111111111111111111111111111111111111111111111111111101 1111111111111111111111111111111111111111111111111111111111111011 1111111111111111111111111111111111111111111111111111111111110111 etc...
In binary, from a field of 64 one bits, one of the bits is set to zero. The complement of this pattern, Walking One, is also available.
The checkerboard pattern looks like this:
1111111111111111111111111111111111111111111111111111111111111111 0000000000000000000000000000000000000000000000000000000000000000 1111111111111111111111111111111111111111111111111111111111111111 0000000000000000000000000000000000000000000000000000000000000000 etc...
In binary, there are 64 1's, followed by 64 0's, and so on. The complement of this pattern is also available.
The address unique pattern looks like this:
0000000000000000000000000000000000000000000000000000000000000000 0001000000000001000000000001000000000001000000000001000000000001 0010000000000010000000000010000000000010000000000010000000000010 0011000000000011000000000011000000000011000000000011000000000011 0100000000000100000000000100000000000100000000000100000000000100 ... 1111111111111111111111111111111111111111111111111111111111111111
This pattern fills the 4096 byte buffer with a unique value in each location. The complement of this pattern is also available.
This parameter causes the entire test to loop several times, or even to loop indefinitely. In the latter case, you can click the interrupt button, and then stop or resume the test. The default is for two loops; it can be useful to loop several times in order to obtain test coverage of pages that were unavailable for testing in earlier loops. Each loop, every available pages is tested even if it has already been tested.
Depending on system load and total memory, and on looping, the test can take a long time to complete. Further, the test will often approach a maximum number of lockable (that is, testable) pages. While the test will continue to re-test pages, it is sometimes useful to end the test when this happens. Progress reports look like this:
16:18:49 Test is 47% through loop 8, on page 4130. 5.4% of the pages lockable and tested (438 of 8192 pages, 2 of 32 Mb).
These reports can be requested at a specified time interval. Alternatively, the test can run free, and when the interrupt button is clicked, a report like the one above is printed, and a dialog lets you abort or continue the test. You can also supplement the periodic reports with interrupt triggered reports.
The help pulldown menu is available at the main tool prompt, or any tool dialog prompt.
When it is entered at the main tool prompt, it starts this help interaction.
When it is entered at a tool dialog prompt, it will display the help for that tool dialog prompt.
The version pulldown menu is available at the main tool prompt. It displays the version and copyright information for the expert tool.
The cancel pulldown menu is available at any tool dialog prompt. It will abort the current dialog and return to the main tool prompt.
The esctoui pulldown menu is available at the main tool prompt or any tool dialog prompt. It will disconnect from the currently executing tool and return to the main UI command level. To reconnect to the tool, use the attach command in the UI.
Hitting Control C (CNTL C) while the tool is executing will cause the following dialog to be displayed:
Interrupted: Enter selA to Abort Tool
selI to Interrupt Tool
selE to Escape to Main UI Command Level
selC to Continue
Selection:
The A selection allows the user to abort the tool.
The tool will be requested to abort and the state of the tool execution in the system map will be set to ABORT_PENDING. When the tool actually exits, it's state will be set to ABORTED.
The E selection allows the user to disconnect from the currently executing tool and return to the main UI command level. To reconnect to the tool, use the attach command in the UI.
The I selection allows the user to interrupt the tool.
When the tool receives the interrupt, it will prompt you if you want to continue with the operation. If the reply is "Continue", the tool resumes what it was doing at the time of the interrupt. If the reply is "Abort", it terminates the operation and returns to the tool's prompt. Since Address Resolution completes so quickly, this button will be most useful for the Memory Test.
The tool may not immediately receive the interrupt as it could be in the middle of an operation that should not or cannot be interrupted. The interrupt will be received as soon as the tool completes the operation.
At that point, a progress report will be displayed in the main window, indicating how many loops have been completed and how many pages have been tested.
The tool will receive and ignore user interrupts when it is already in the process of returning to the main tool prompt.
The C selection allows the user to continue will tool execution. The tool will continue execution just as if the Control C had not been hit.