Datasheet

■ The alias word at 0x2200.0000 maps to bit 0 of the bit-band byte at 0x2000.0000:

0x2200.0000 = 0x2200.0000 + (0*32) + (0*4)

■ The alias word at 0x2200.001C maps to bit 7 of the bit-band byte at 0x2000.0000:

0x2200.001C = 0x2200.0000+ (0*32) + (7*4)

Figure 2-4. Bit-Band Mapping

0x23FF.FFE4

0x2200.0004

0x23FF.FFE00x23FF.FFE80x23FF.FFEC0x23FF.FFF00x23FF.FFF40x23FF.FFF80x23FF.FFFC

0x2200.00000x2200.00140x2200.00180x2200.001C 0x2200.00080x2200.0010 0x2200.000C

32-MB Alias Region

7 0

0x2000.00000x2000.00010x2000.00020x2000.0003

6 5 4 3 2 1 07 6 5 4 3 2 1 7 6 5 4 3 2 1 07 6 5 4 3 2 1

07 6 5 4 3 2 1 6 5 4 3 2 107 6 5 4 3 2 1 07 6 5 4 3 2 1

0x200F.FFFC0x200F.FFFD0x200F.FFFE0x200F.FFFF

1-MB SRAM Bit-Band Region

2.4.5.1 Directly Accessing an Alias Region

Writing to a word in the alias region updates a single bit in the bit-band region.

Bit 0 of the value written to a word in the alias region determines the value written to the targeted

bit in the bit-band region. Writing a value with bit 0 set writes a 1 to the bit-band bit, and writing a

value with bit 0 clear writes a 0 to the bit-band bit.

Bits 31:1 of the alias word have no effect on the bit-band bit. Writing 0x01 has the same effect as

writing 0xFF. Writing 0x00 has the same effect as writing 0x0E.

When reading a word in the alias region, 0x0000.0000 indicates that the targeted bit in the bit-band

region is clear and 0x0000.0001 indicates that the targeted bit in the bit-band region is set.

2.4.5.2 Directly Accessing a Bit-Band Region

“Behavior of Memory Accesses” on page 77 describes the behavior of direct byte, halfword, or word

accesses to the bit-band regions.

2.4.6 Data Storage

The processor views memory as a linear collection of bytes numbered in ascending order from zero.

For example, bytes 0-3 hold the first stored word, and bytes 4-7 hold the second stored word. Data

is stored in little-endian format, with the least-significant byte (lsbyte) of a word stored at the

81June 18, 2012

Texas Instruments-Production Data

Stellaris

LM3S8962 Microcontroller

NRND: Not recommended for new designs.