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Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors—Internal Buses
Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
Developer’s Manual
August 2006
226
Order Number: 306262-004US
5.2
Memory Map
shows the memory map of peripherals connected to the AHB.
Table 98.
Bus Arbitration Example: Three Requesting Masters
Initial
+1
+2
+3
+4
+5
+6
+7
+8
+9
Requesting
Masters
XYZ
YZ
ZX
XY
YZ
ZX
XY
YZ
ZX
XY
Winning Bus
Initiator
-
X
Y
Z
X
Y
Z
X
Y
Z
Table 99.
Memory Map (Sheet 1 of 2)
Start Address
End Address
Size
Use
0000_0000
0FFF_FFFF
256 MB
Expansion Bus Data (Mirrored)
0000_0000
3FFF_FFFF
1024 MB
DDRI-266 SDRAM Data
4000_0000
47FF_FFFF
128 MB
(Reserved)
4800_0000
4FFF_FFFF
128 MB
PCI Data
5000_0000
5FFF_FFFF
256 MB
Expansion Bus Data
6000_0000
63FF_FFFF
64 MB
Queue manager
6400_0000
BFFF_FFFF
(Reserved)
C000_0000
C3FF_FFFF
64 MB
PCI Controller Configuration and Status Registers
C400_0000
C7FF_FFFF
64 MB
Expansion Bus Configuration Registers
C800_0000
C800_0FFF
1 KB
UART0
C800_1000
C800_1FFF
1 KB
UART1
C800_2000
C800_2FFF
1 KB
Internal Bus Performance Monitoring Unit
C800_3000
C800_3FFF
1 KB
Interrupt Controller
C800_4000
C800_4FFF
1 KB
GPIO Controller
C800_5000
C800_5FFF
1 KB
Timers
C800_6000
C800_6FFF
1 KB
NPE-A (Intel
®
IXP400 Software Definition)– Not
User Programmable
C800_7000
C800_7FFF
1 KB
NPE-B (IXP400 software Definition) – Not User
Programmable
Notes:
1.
The lowest 256 Mbyte of address space is configurable based on the value of a configuration
register located in the Expansion Bus Controller.
2.
When bit 31 (MEM_MAP) of configuration register #0 (EXP_CFG0) is set to logic 1, the Expansion
Bus occupies the lowest 256 Mbyte of address space.
• When bit 31 (MEM_MAP) of configuration register #0 (EXP_CFG0) is set to logic 0 the
Expansion Bus occupies 256MB of address space starting at 5000_0000 while the DDRI
SDRAM occupies the lower 256 Mbyte of address.
• In both cases, regardless of the value of MEM_MAP, the DDRI SDRAM occupies the
768 MB (from 1000_0000 to 3FFF_FFFF) immediately following the lowest 256 Mbyte
and the Expansion Bus can be accessed starting at address 5000_0000.
• On reset, the configuration register in the Expansion Bus will be set to logic 1. This
setting is required because the dedicated boot memory is flash memory located on the
Expansion Bus.