Digital Test Patterns
Test Patterns
There are a numbers of ways to check for design or build issues with a
data bus.
Send a pattern of alternating 0x5's and 0xA's; over the data
bus.
Checks for bits stuck high or low [0101, followed by
1010]
Send a pattern of 0x0 and 0xF;. over the data bus.
Checks for bits stuck high or low [0000, followed by
1111]
Checks for ground bounce issues with the input of the
driver
Send a pattern of 0x0 and 0xE;. over the data bus.
Checks for ground bounce issues with the output of the driver
[0000, followed by 1110]
A four bit data bus is shown, but it's the same regardless of the bus
width. Just keep the pattern true for the width of the driver chip. The
exception is the 0xE, if the driver IC is 8-bits wide send 0xFE, not
0xEE.
Additional Digital Logic Pitfalls, Design for Test.
