6-4
MCF5272 User’s Manual
Programming Model
6.2.2 Module Base Address Register (MBAR)
The supervisor-level MBAR, Figure 6-2, specifies the base address and allowable access
types for all internal peripherals. It is written with a MOVEC instruction using the CPU
address 0xC0F. (See the ColdFire Family Programmer’s Reference Manual.) MBAR can
be read or written through the debug module as a read/write register, as described in.” Once
MBAR has been initialized, it can be read and written in supervisor mode at the address
programmed into the base address (BA) field.
The valid bit, MBAR[V], is cleared at system reset to prevent incorrect references before
MBAR is written; other MBAR bits are uninitialized at reset. To access internal peripherals,
write MBAR with the appropriate base address (BA) and set MBAR[V] after system reset.
All internal peripheral registers occupy a single relocatable memory block along 64-Kbyte
boundaries. If MBAR[V] is set, MBAR[BA] is compared to the upper 16 bits of the full
32-bit internal address to determine if an internal peripheral is being accessed. MBAR
masks specific address spaces using the address space fields. Attempts to access a masked
address space generate an external bus access.
Addresses hitting overlapping memory spaces take the following priority:
1. SRAM, ROM, and cache
2. MBAR
3. Chip select
Thus, if an overlapping address hits in the SRAM, ROM, or cache, the SIM will not
generate a bus cycle, either externally or to an on-chip peripheral.
NOTE:
The MBAR region must be mapped to non-cacheable space.
Table 6-2 describes MBAR fields.
31
16 15
5
4
3
2
1
0
Field
BA
—
SC SD UC UD V
Reset
Undefined
0
R/W
W initially through MOVEC; R/W after initialization in supervisor mode
Address
CPU + 0x0C0F initially; MBAR+0x000 after initialization
Figure 6-2. Module Base Address Register (MBAR)
Attribute Mask Bits
Содержание DigitalDNA ColdFire MCF5272
Страница 1: ...MCF5272UM D Rev 0 02 2001 MCF5272 ColdFire Integrated Microprocessor User s Manual ...
Страница 38: ...xxxviii MCF5272 User s Manual TABLES Table Number Title Page Number ...
Страница 58: ...1 10 MCF5272 User s Manual MCF5272 Specific Features ...
Страница 90: ...2 42 MCF5272 User s Manual Exception Processing Overview ...
Страница 96: ...3 6 MCF5272 User s Manual MAC Instruction Execution Timings ...
Страница 158: ...5 46 MCF5272 User s Manual Motorola Recommended BDM Pinout ...
Страница 184: ...7 12 MCF5272 User s Manual Interrupt Controller Registers ...
Страница 338: ...13 44 MCF5272 User s Manual Application Examples ...
Страница 414: ...18 6 MCF5272 User s Manual PWM Programming Model ...
Страница 452: ...19 38 MCF5272 User s Manual Power Supply Pins ...
Страница 482: ...20 30 MCF5272 User s Manual Reset Operation ...
Страница 492: ...21 10 MCF5272 User s Manual Non IEEE 1149 1 Operation ...
Страница 548: ...INDEX Index 12 MCF5272 User s Manual ...