Table 3-7. Powerpc 60X To Rom/Flash Address Mapping With Two - Motorola MVME2600 Series Reference Manual

b. only single-byte writes are allowed (all other sizes are ignored),
c. all reads are allowed (multiple accesses are performed to the
When the device type status bit is set, the block's ROM/Flash is
considered to be two 32-bit read/write devices or one 64-bit read-
only device. If two 32-bit devices are being used, then one device is
connected to each Falcon and the following rules are enforced:
a. only aligned, 4-byte writes should be attempted (all other sizes
b. all reads are allowed (multiple accesses to the ROM/Flash
If one 64-bit device is being used, then control for the device is
connected to either Falcon while half of the data is connected to the
upper Falcon and half of the data is connected to the lower Falcon.
The following rules are enforced:
a. no writes should be attempted (aligned, 4-byte, writes are
b. all reads are allowed (multiple accesses to the ROM/Flash
More information about ROM/Flash is found in the section on the
Programming Model in this chapter.
In order to place code correctly in the ROM/Flash devices, address
mapping information is required. Table 3-7 shows how PowerPC 60x
addresses map to the ROM/Flash addresses with two 8-bit devices. Table
3-8 shows how they map with two 32-bit devices or one 64-bit (read-only)
device.
Table 3-7. PowerPC 60x to ROM/Flash Address Mapping with Two 8-bit Devices
PowerPC 60x A0-A31
$XX000000
$XX000001
and
ROM/Flash devices when the read is for greater than one byte).
are ignored), and
device are performed for burst reads).
allowed but produce undefined results, all other sizes are
ignored), and
device are performed for burst reads).
ROM/Flash A22-A0
$000000
$000001
Functional Description
ROM/Flash Device Selected
Upper
Upper
3
3-17