Motorola MPC533 Reference Manual page 416

Programming Model
Bits Name
0 — Reserved
1:6 AM Address mask. The address mask field of each option register provides for masking any of the
corresponding bits in the associated base register. By masking the address bits independently,
external devices of different size address ranges can be used. Any clear bit masks the
corresponding address bit. Any set causes the corresponding address bit to be used in the
comparison with the address signals. Address mask bits can be set or cleared in any order in
the field, allowing a resource to reside in more than one area of the address map. This field can
be read or written at any time.
7:9 — Reserved
10:12 ATM Address type mask. This field can be used to mask certain address type bits, allowing more
than one address space type to be assigned to a chip select. Any set bit causes the
corresponding address type code bits to be used as part of the address comparison. Any
cleared bit masks the corresponding address type code bit.
To instruct the memory controller to ignore address type codes as part of the address
comparison, clear the ATM bits.
NOTE: Following a system reset, the ATM bits are cleared in DMOR, except the ATM2 bit. This
means that only data accesses are dual mapped. Refer to the address types definition in
Table 9-8.
13:31 — Reserved
10-40
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
Table 10-13. DMOR Bit Descriptions
MPC533 Reference Manual
Description
MOTOROLA