Embedded Design Handbook

ID 683689
Date 8/28/2023
Public
Document Table of Contents

6.3.2.1.2. Address Trace Failure

The address trace test is similar to the walking ones test used for data with one exception. For this test you must write to all the test locations before reading back the data. Using address locations that are powers of two, you can quickly verify all the address traces of your circuit board.

The address trace test detects the aliasing effects that short or open circuits can have on your memory interface. For this reason it is important to write to each location with a different data value so that you can detect the address aliasing. You can use increasing numbers such as 1, 2, 3, 4, and so on while you verify the address traces in your system. The table below shows how to use powers of two in the process of finding an address trace failure:

Table 51.  Powers of Two Example
Address Written Value Read Value Failure Detected
00000000 1 1 No failure detected
00000001 2 2 No failure detected
00000010 3 3 Error, the second address bit, A[1], is stuck low
00000100 4 4 No failure detected
00001000 5 5 No failure detected
00010000 6 6 No failure detected
00100000 7 7 Error, A[5] and A[4] are short circuited
01000000 8 8 No failure detected
10000000 9 9 No failure detected