Memory Interface Configuration Registers; Memory Boundary Registers - Motorola MPC8240 User Manual

Table 4-19. Embedded Utilities Memory Base Address Register—0x78
Bits Name
msb Base Address 0x000
31–20
19–0 — 0x0_0000 Reserved
4.6 Memory Interface Configuration Registers
The memory interface configuration registers (MICRs) control memory boundaries
(starting and ending addresses), memory bank enables, memory timing, and external
memory buffers. Initialization software must program the MICRs at reset and then enable
the memory interface on the MPC8240 by setting the MEMGO bit in memory control
configuration register 1 (MCCR1).

4.6.1 Memory Boundary Registers

The extended starting address and the starting address registers are used to define the lower
address boundary for each memory bank. The lower boundary is determined by the
following formula:
Lower boundary for bank n = 0b00 || <extended starting address n> || <starting address n>
|| 0x0_0000.
The extended ending address and the ending address registers are used to define the upper
address boundary for each memory bank. The upper boundary is determined by the
following formula:
Upper boundary for bank n = 0b00 || <extended ending address n> || <ending address n> ||
0xF_FFFF.
Figure 4-7, Figure 4-8, and Table 4-20 depict the memory starting address register 1 and 2
bit settings.
Starting Address Bank 3 Starting Address Bank 2 Starting Address Bank 1 Starting Address Bank 0
31
Figure 4-7. Memory Starting Address Register 1—0x80
Reset
Value
Base address of the embedded memory utilities block. The block size is 1 Mbyte,
and its base address is aligned naturally to a 1 Mbyte address boundary (so the
base address is 0xXXX0_0000). This block is used by processor-initiated
transactions and should be located within PCI memory space.
Registers within the EUMB are located from 0x8000_0000 to 0xFDFF_FFFF
Thus, valid values are 0x800–0xFDF. Otherwise, the EUMB is effectively disabled.
24 23
Chapter 4. Configuration Registers
Memory Interface Configuration Registers
Description
16 15 8
.
7 0
4-23