FBD Channel Interface
2.3.3
Recalibrate State Considerations
In addition to what the FBD Architecture and Protocol specification describes around
Recalibrate State, the AMB further requires that the host be sending NOP commands in
at least the 2 frames preceding the exit from recalibrate state.
Requirement: 2 Cycles before the recalibrate counter expires, NOPs must be sent from
the host.
Recal Frame
Counter
Time
Frame Description
N
Sync with ERC bit set
NOP frame
0
N+1
N+2
...
RECALDUR
RECALDUR - 1
....
NOP frame
NOP frame
N+8
N+9
...
NOP frame
RECALDUR - 7
RECALDUR - 8
....
NOP frame - host may begin recalibration
.....
N + RECALDUR - NOP frame - host must be finished with recalibration
7
8
...
.....
....
4
N + RECALDUR - NOP frame
3
N + RECALDUR - NOP frame
2
3
2
N + RECALDUR - NOP frame - must be received at AMB without corruption
1
N + RECALDUR
0
NOP frame - must be received at AMB without corruption
Valid Sync Frame
1
0
Recal Frame Counter:54 3
Rx Data:X
2
1
0
X
X
NOP
NOP
Valid Cmd
where X represents “don’t care” data
18
Intel® 6400/6402 Advanced Memory Buffer Datasheet
INTEL [ INTEL ]
