Local Memory Base Address Register (Lmbar); Inbound Translation Window Register (Itwr) - Motorola MPC8240 User Manual

3.3.3.1 Local Memory Base Address Register (LMBAR)

The LMBAR, shown in Figure 3-8 and Table 3-8, defines the inbound memory window.
Reserved
Inbound Memory Base Address
31
Figure 3-8. Local Memory Base Address Register (LMBAR)—0x10
Bits Name
31–12 Inbound 0x0000_0 R/W
memory base
address
11–4 — All 0s
3 Prefetchable 1
2–1 Type 00
0 Memory 0
space
indicator

3.3.3.2 Inbound Translation Window Register (ITWR)

The ITWR, shown in Figure 3-9 and Table 3-9, defines the inbound translation window and
the inbound window size. The inbound window size in the ITWR sets the size of both the
inbound translation window in local memory and the inbound memory window in PCI
memory space. Software can alter the inbound translation base address in the ITWR during
run-time to access different portions of local memory. Because the inbound memory base
address in the LMBAR should be aligned to the inbound window size in the ITWR, the
inbound window size should not be changed without also updating the LMBAR. As a
general rule, the ITWR should be programmed before programming the LMBAR.
0
31 30
Figure 3-9. Inbound Translation Window Register (ITWR)
Table 3-8. Bit Settings for LMBAR—0x10
Reset
R/W
Value
Indicates the base address where the inbound memory window resides.
The inbound memory window should be aligned based on the
granularity specified by the inbound window size specified in the ITWR.
Note that the EUMB area must be selected first, then the ITWR
programmed, and then these bits can be set.
R Reserved; the MPC8240 only allows a minimum of a 4KByte window.
R Indicates that the space is prefetchable.
R The inbound memory window may be located anywhere within the
32-bit PCI address space.
R Indicates PCI memory space.
Inbound Translation Base Address
Chapter 3. Address Maps
Address Translation
Memory Space Indicator
Type
Prefetchable
0 0 0 0 0 0 0 0
12 11
Description
Inbound Window Size
0 0 0 0 0 0 0
12 11 5
1 00 0
4 3 2 1 0
Reserved
4 0
3-15