DDR MemBIST
Figure 11-3. Fast X Address Sequencing
One Bank
Address space as set by values in MTR register
Address space as set by start and end values in
MB_START_ADDR and MB_END_ADDR registers
E
16
17
13
14
15
10
11
12
7
8
9
4
5
6
1
2
3
S
18
Increasing X
0
0
Increasing Y
0001
Fast X address sequencing, decreasing
address, specified address range
11.3.2.4.3
Fast XY
In Fast XY execution, both the X and Y address counters are changed by one count at
the same time. Each of these counters begins at its starting address and increments to
its ending address (or decrements from ending to starting address if so programmed)
and then reloads on the next count to its initial value. As a result, test execution
accesses the RAM locations in diagonal rows across the RAM. Execution stops when
both the X and Y address counters reach their end values simultaneously.
In the special case when there are the same number of rows and columns in the
address space, only the locations on the diagonal (whose relative row and column
positions are equal) will be tested. In the general case in which the specified address
range results in different numbers of rows and columns, not all locations may be
accessed. Which locations are accessed in this case depends upon the X to Y ratio of
the address space specified for the test. See Figure 11-4 below for several examples.
Because the starting and ending addresses are always located at opposite corners of
the address space, the end address is always eventually reached, and the MemBIST
operation always completes.
120
Intel® 6400/6402 Advanced Memory Buffer Datasheet
INTEL [ INTEL ]
