Freescale Semiconductor MPC8260 - Manual (Page 209)

System Interface Unit (SIU)
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor 4-37
4.3.2.8 System Protection Control Register (SYPCR)
The system protection control register, shown in Figure 4-30 , controls the system monitors, software
watchdog period, and bus monitor timing. SYPCR can be read at any time but can be written only once
after system reset.
Table 4-13. IMMR Field Descriptions
Bits Name Description
0–14 ISB Internal space base. Defines the base address of the internal memory space. The value of ISB
is configured at reset to one of eight addresses; it can then be changed to any value by the
software. The default is 0, which maps to address 0x0000_0000. (See
Section 5.4.1, “Hard
Reset Configuration Word.” )
ISB defines the 15 msbs of the memory map register base address. IMMR itself is mapped in
the internal memory space region. As soon as the ISB is written with a new base address, the
IMMR base address is relocated according to the ISB. ISB can be configured to one of eight
possible addresses at reset to enable the configuration of multiple-PowerQUICC II systems.
The number of programmable bits in this field, and hence the resolution of the location of
internal space, depends on the internal memory space of a specific implementation. In the
PowerQUICC II, all 15 bits can be programmed. See
Chapter 3, “Memory Map,” for details on
the device’s internal memory map and to Chapter 5, “Reset,” for the available, default initial
values.
15 — Reserved, should be cleared.
16–23 PARTNUM Part number. This read-only field is mask-programmed with a code corresponding to the part
number of the part on which the SIU is located. It is intended to help factory test and user code
which is sensitive to part changes. This changes when the part number changes. For example,
it would change if any new module is added or if the size of any memory module is changed. It
would not change if the part is changed to fix a bug in an existing module. The PowerQUICC II
has an ID of 0x00.
24–31 MASKNUM Mask number. This read-only field is mask-programmed with a code corresponding to the mask
number of the part on which the SIU is located. It is intended to help factory test and user code
which is sensitive to part changes. It is programmed in a commonly changed layer and should
be changed for all mask set changes.
0 15
Field SWTC
Reset 1111_1111_1111_1111
R/W R/W
Addr 0x0x10004
16 23 24 25 26 28 29 30 31
Field BMT PBME LBME — SWE SWRI SWP
Reset 1111_1111 0 0 00_0 1 1 1
R/W R/W
Addr 0x10006
Figure 4-30. System Protection Control Register (SYPCCR)