Datasheet

Table 2-6. SRAM Memory Bit-Banding Regions
Instruction and Data AccessesMemory Region
Address Range
EndStart
Direct accesses to this memory range behave as SRAM
memory accesses, but this region is also bit addressable
through bit-band alias.
SRAM bit-band region0x2000.FFFF0x2000.0000
Data accesses to this region are remapped to bit band
region. A write operation is performed as
read-modify-write. Instruction accesses are not remapped.
SRAM bit-band alias0x221F.FFFF0x2200.0000
Table 2-7. Peripheral Memory Bit-Banding Regions
Instruction and Data AccessesMemory Region
Address Range
EndStart
Direct accesses to this memory range behave as
peripheral memory accesses, but this region is also bit
addressable through bit-band alias.
Peripheral bit-band
region
0x400F.FFFF0x4000.0000
Data accesses to this region are remapped to bit band
region. A write operation is performed as
read-modify-write. Instruction accesses are not permitted.
Peripheral bit-band alias0x43FF.FFFF0x4200.0000
The following formula shows how the alias region maps onto the bit-band region:
bit_word_offset = (byte_offset x 32) + (bit_number x 4)
bit_word_addr = bit_band_base + bit_word_offset
where:
bit_word_offset
The position of the target bit in the bit-band memory region.
bit_word_addr
The address of the word in the alias memory region that maps to the targeted bit.
bit_band_base
The starting address of the alias region.
byte_offset
The number of the byte in the bit-band region that contains the targeted bit.
bit_number
The bit position, 0-7, of the targeted bit.
Figure 2-4 on page 81 shows examples of bit-band mapping between the SRAM bit-band alias
region and the SRAM bit-band region:
■ The alias word at 0x23FF.FFE0 maps to bit 0 of the bit-band byte at 0x200F.FFFF:
0x23FF.FFE0 = 0x2200.0000 + (0x000F.FFFF*32) + (0*4)
■ The alias word at 0x23FF.FFFC maps to bit 7 of the bit-band byte at 0x200F.FFFF:
0x23FF.FFFC = 0x2200.0000 + (0x000F.FFFF*32) + (7*4)
June 18, 201280
Texas Instruments-Production Data
The Cortex-M3 Processor
NRND: Not recommended for new designs.