Intel IXP42X Personal Computer User Manual


 
Intel
®
IXP42X product line and IXC1100 control plane processors—SDRAM Controller
Intel
®
IXP42X Product Line of Network Processors and IXC1100 Control Plane Processor
DM September 2006
290 Order Number: 252480-006US
These are the commands issued by the memory controller to the SDRAM and are not
accessible through the AHB (i.e. a master cannot issue these commands on the internal
bus to the memory controller unit).
§ §
4A1A0
0 0 0-1-2-3 0-1-2-3
0 1 1-2-3-0 1-0-3-2
1 0 2-3-0-1 2-3-0-1
1 1 3-0-1-2 3-2-1-0
8A2A1A0
0 0 0 0-1-2-3-4-5-6-7 0-1-2-3-4-5-6-7
0 0 1 1-2-3-4-5-6-7-0 1-0-3-2-5-4-7-6
0 1 0 2-3-4-5-6-7-0-1 2-3-0-1-7-6-5-4
0 1 1 3-4-5-6-7-0-1-2 3-2-1-0-7-6-5-4
1 0 0 4-5-6-7-0-1-2-3 4-5-6-7-0-1-2-3
1 0 1 5-6-7-0-1-2-3-4 5-4-7-6-1-0-3-2
1 1 0 6-7-0-1-2-3-4-5 6-7-5-4-2-3-0-1
1 1 1 7-0-1-2-3-4-5-6 7-6-5-4-3-2-1-0
Table 115. SDRAM Burst Definitions
Burst Length Starting Column Address
Order of Accesses within a Burst
Type = Sequential Type = Interleaved
Table 116. SDRAM Commands
Command CS# RAS# CAS# WE# DQM ADDR DATA
COMMAND INHIBIT H X X X X X
NO OPERATION L H H H X X
ACTIVE L L H H X Bank/Row
*
READ L H L H X Bank/Col
WRITE L H L L X Bank/Col VALID
BURST TERMINATE L H H L X X ACTIVE
PRECHARGE L L H L X CODE
AUTO REFRESH OR
SELF REFRESH
LL L H X X
LOAD MODE
REGISTER
LL L L X
BA = 00
ADDR =
opcode
WRITE ENABLE/
OUTPUT ENABLE
-- - - L -ACTIVE
WRITE INHIBIT/
OUTPUT HIGH-Z
-- - - H -HIGH-Z
Note: Bank is used in the “SDRAM” sense, synonymous to LEAF in the rest of the documentation.