LM3S1H11 Datasheet, PDF (123/956 Pages) Texas Instruments – Stellaris® LM3S1H11 Microcontroller

Stellaris^® LM3S1H11 Microcontroller
Register 29: Auxiliary Control (ACTLR), offset 0x008
Note: This register can only be accessed from privileged mode.
The ACTLR register provides disable bits for IT folding, write buffer use for accesses to the default
memory map, and interruption of multi-cycle instructions. By default, this register is set to provide
optimum performance from the Cortex-M3 processor and does not normally require modification.
Auxiliary Control (ACTLR)
Base 0xE000.E000
Offset 0x008
Type R/W, reset 0x0000.0000
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
reserved
Type RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
reserved
DISFOLD DISWBUF DISMCYC
Type RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
R/W
R/W
R/W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Bit/Field
31:3
2
1
Name
reserved
DISFOLD
DISWBUF
Type
RO
R/W
R/W
Reset
0x00
0
0
Description
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
Disable IT Folding
Value Description
0 No effect.
1 Disables IT folding.
In some situations, the processor can start executing the first instruction
in an IT block while it is still executing the IT instruction. This behavior
is called IT folding, and improves performance, However, IT folding can
cause jitter in looping. If a task must avoid jitter, set the DISFOLD bit
before executing the task, to disable IT folding.
Disable Write Buffer
Value Description
0 No effect.
1 Disables write buffer use during default memory map accesses.
In this situation, all bus faults are precise bus faults but
performance is decreased because any store to memory must
complete before the processor can execute the next instruction.
Note: This bit only affects write buffers implemented in the
Cortex-M3 processor.
January 23, 2012
123
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