6402 datasheet(117/250 Pages) INTEL

117 / 250 page

Intel® 6400/6402 Advanced Memory Buffer Datasheet

117

DDR MemBIST

As the figure above illustrates, when the values of the MB_START_ADDR (marked S)

and MB_END_ADDR (marked E) registers are used to set the address space for a

MemBIST operation, the values in these registers must bear the correct relationship to

each other. The start address sets the lower bound for the test address space in both

the X and Y directions, and the end address sets the upper bound in both the X and Y

directions. For a start and end address to define a usable address space, it is required

that Xs < Xe, and Ys < Ye. In addition, when an address sequencing mode is chosen in

which the bank field in MB_END_ADDR is significant, it is also required that Zs < Ze. (If

a single physical address is to be tested, MBADDR, not MB_START_ADDR and

MB_END_ADDR, is used.)

In every case in which an address endpoint is specified using a register value,

MemBIST includes the address endpoint in the operation. For example, if an address

range is specified using the MB_START_ADDR and MB_END_ADDR registers, the

locations specified in these registers are included as part of the address range. The

MemBIST operation will be performed on both of the locations specified in these

registers.

11.3.2.3.1

Order and Direction of Address Sequencing

The order of sequencing through the test address space is chosen using the

MBCSR:fast field. The options are Fast Y (with fixed bank), Fast X (with fixed bank),

Fast XY (with fixed bank) and XZY. The terms Fast X, Fast Y, Fast XY and XZY refer to

the order in which addresses are incremented or decremented during MemBIST

execution. This order is given in Table 11-4 above as “counter order.” Counter order of

XZY, for example, indicates that the Y counter is counted most rapidly. When counter Y

over or underflows due to reaching the programmed limit of its count, the overflow or

Figure 11-1. Range and Full Address Spaces

One Bank

0 Increasing Y

Increasing X

Limit of address space as set by number of X and Y address lines

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

0001

6402 Datasheet(PDF) 117 Page - Intel Corporation