Window Into Configuration Space; Local Access Windows; Local Access Register Memory Map - Freescale Semiconductor MPC8313E Family Reference Manual

System Configuration
5.2.2

Window into Configuration Space

The internal memory map registers' base address register (IMMRBAR) defines a window that is used to
access all memory-mapped configuration, control, and status registers, referred to as internal memory map
registers or IMMR. This window is always enabled with a fixed size of 1 Mbyte, and no other attributes
are attached so there is no associated size/attribute register. This window always takes precedence over all
local access windows. The IMMRBAR always come out of reset with a default base address value of
0xFF40_0000, and this base address value can be modified by writing to this register. For more
information, see Section 5.2.4.1, "Internal Memory Map Registers Base Address Register (IMMRBAR)."
Although it is legal to use the 3-Mbyte space consecutive to the 1 Mbyte of
the IMMR (for example, if IMMRBAR is 0xFF40_0000, the 3-Mbyte
address space consecutive to it is 0xFF50_0000–0xFF7F_FFFF), it is not
recommended. This space may be used in future derivatives of the device
that require a larger internal memory space.
5.2.3

Local Access Windows

As demonstrated in the address map overview in
Example," local access windows associate a range of the local 32-bit address space with a particular target
interface. This allows the internal interconnections of the device to route a transaction from its source to
the proper target. No address translation is performed. The base address defines the high order address bits
that give the location of the window in the local address space. The window attributes enable the window
and define its size, while the window number specifies the target interface.
With the exception of configuration space (mapped by IMMRBAR), all addresses used by the system must
be mapped by a local access window. This includes addresses that are mapped by PCI inbound windows.
The local access window registers exist as part of the local access block in the system configuration
registers. See Section 5.3.2, "System Configuration Registers."
window registers is given in the following sections. Note that the minimum size of a window is 4 Kbytes,
so the low order 12 bits of the base address cannot be specified.
5.2.3.1

Local Access Register Memory Map

Table 5-4 shows the memory map for the local access registers.
Local Memory
Offset (Hex)
0x0_0000 Internal memory map base address register (IMMRBAR)
0x0_0004 Reserved
0x0_0008 Alternate configuration base address register (ALTCBAR)
0x0_000C– Reserved
0x0_001C
MPC8313E PowerQUICC II Pro Integrated Processor Family Reference Manual, Rev. 3
5-4
NOTE
Section 5.2, "Local Memory Map Overview and
Table 5-4. Local Access Register Memory Map
Register
A detailed description of the local access
Access Reset
R/W 0xFF40_0000
— —
R/W 0x0000_0000
— —
Freescale Semiconductor
Section/Page
5.2.4.1/5-6
—
5.2.4.2/5-7
—