LM3S608-IQN50-C2 Datasheet, PDF (65/538 Pages) Texas Instruments – Stellaris LM3S608 Microcontroller

NRND: Not recommended for new designs.
Stellaris^® LM3S608 Microcontroller
Figure 2-4. Bit-Band Mapping
32-MB Alias Region
0x23FF.FFFC 0x23FF.FFF8 0x23FF.FFF4 0x23FF.FFF0 0x23FF.FFEC 0x23FF.FFE8 0x23FF.FFE4 0x23FF.FFE0
0x2200.001C 0x2200.0018 0x2200.0014 0x2200.0010 0x2200.000C 0x2200.0008 0x2200.0004 0x2200.0000
1-MB SRAM Bit-Band Region
76543210765432107654321076543210
0x200F.FFFF
0x200F.FFFE
0x200F.FFFD
0x200F.FFFC
76543210765432107654321076543210
0x2000.0003
0x2000.0002
0x2000.0001
0x2000.0000
2.4.5.1
2.4.5.2
2.4.6
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.
Directly Accessing a Bit-Band Region
“Behavior of Memory Accesses” on page 61 describes the behavior of direct byte, halfword, or word
accesses to the bit-band regions.
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
lowest-numbered byte, and the most-significant byte (msbyte) stored at the highest-numbered byte.
Figure 2-5 on page 66 illustrates how data is stored.
June 18, 2012
65
Texas Instruments-Production Data