Address lines

To force bit flips in address lines, the test uses three approaches:

• Sequential- This approach works sequentially through all of the memory under test, from lowest address to highest address. This sequential approach results in an average number of bit flips from one access to the next.
• Full Range Converging- This approach works from the fringes of the memory range toward the middle of the memory range. Memory access proceeds in this pattern, where +  number and -  number refer to the next item location (the specific increment or decrement depends on byte, word, or long word address mode):
  • the lowest address
  • the highest address
  • (the lowest address) + 1
  • (the highest address) - 1
  • (the lowest address) + 2
  • (the highest address) - 2
• Maximum Invert Convergence- This approach uses calculated end point addresses to maximize the number of bits flipping from one access to the next. This approach involves identifying address end points such that the values have the maximum inverted bits relative to one another. Specifically, the test identifies the lowest address with all 0x5 values in the least significant nibbles and the highest address with all 0xA values in the least significant nibbles. After the test identifies these end points, memory access alternates between low address and high address, working towards the center of the memory under test. Accessing memory in this manner, the test achieves the maximum number of bits flips from one access to the next.