Figure - Interphase 4538 Hardware Reference Manual

Chapter 1: Hardware Description
local processor can also be cachable. The peripherals cannot be cachable. The area of
SDRAM memory used for the transfer of data cannot be cachable either, because it can be
modified by elements other than the PowerQUICC II, such as the PowerSpan DMA.
In order to simultaneously support cachable and non cachable areas in the SDRAM
memories, they are mapped twice in the local space. One mapping area will be defined as
cachable and the other will be defined as non cachable.
Table 1-1 and

Figure 1-2

indicate the organization of the local space as defined in the
current 4538 Boot Firmware code, with the instruction and data BAT blocks and CS banks
used.
Table 1-1. PCI Local Space Mapping
IBAT/ CS
Address Area Size Element Accessed DBAT Bank Property
5
4538 Hardware Reference Manual