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Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
August 2006
Developer’s Manual
Order Number: 306262-004US
607
Memory Controller—Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
1. Each of the MCU inbound memory transaction ports decodes the address to
determine if the transaction should be claimed.
— If the address falls in the DDRI SDRAM address range indicated by the SDBR,
SBR0, SBR1, and S32SR, the MCU claims the transaction and latches the
transaction in the respective memory transaction queue.
2. Once the MARB selects the highest priority transaction from the memory
transaction queues, it forwards the transaction to the DDRI SDRAM control block.
The DDRI SDRAM Control Block decodes the address to determine whether or not
any of the open pages are hit.
Figure 114. DDRI SDRAM Read, 36 Bytes, ECC Enabled, BL=4
B0405-02
CKE
CK
CK_N
Command
Valid
t
CH
t
CK
t
CL
t
IS
t
IH
NOP
ACT
NOP
Read
NOP
NOP
NOP
NOP
RA
BA x
RA
COL n
NOP
ACT
NOP
t
IS
t
IH
RA
BA x
t
IS
t
IH
t
IS
t
IH
t
AC
A0-A9,
A11, A12
A10
Notes:
Do n = data out from column n.
3 subsequent elements of data out are provided in the programmed order following Do n.
DIS AP = Disable Auto Precharge
* = Don't care if A10 is High at this point.
PRE = Precharge; ACT = Active; RA = Row Address; BA = Bank Address
NOP commands are shown for ease of illustration; other valid commands may be possible at these times
= Don't Care
One Bank
All Banks
t
IS
t
IH
t
RPRE
t
RP
t
LZ
(min)
t
AZ
(min)
Do n
Do n
t
DQSCK
(min)
CL=2
t
LZ
(min)
BA0, BA1
DM
DQS
DQ
Case 1:
t
AC/
t
DQSCK
=min
BA x
BA x*
t
RCD
t
RAS
t
LZ
(max)
DQS
DQ
Case 2:
t
AC/
t
DQSCK
=max
RA
t
LZ
(max)
DIS AP
t
RPRE
t
AC
(max)
t
DQSCK
(max)