Programming Model
1609
SPRUHE8E – October 2012 – Revised November 2019
Copyright © 2012–2019, Texas Instruments Incorporated
Cortex-M3 Processor
24.4.4 Register Descriptions
This section lists and describes the Cortex-M3 registers, in the order shown in
. The core
registers are not memory mapped and are accessed by register name rather than offset.
Note:
The register type shown in the register descriptions refers to type during program execution in
thread mode and handler mode. Debug access can differ.
24.4.4.1 Cortex General-Purpose Registers 0-12 (Core R0-R12)
The Core registers (R
n
) are 32-bit general-purpose registers for data operations and can be accessed
from either privileged or unprivileged mode.
Figure 24-3. Cortex General-Purpose Registers 0-12 (R0-R12)
31
0
DATA
R/W
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 24-3. Cortex General-Purpose Registers 0-12 (R0-R12) Field Descriptions
Bit
Field
Value
Description
31-0
DATA
Register data.
24.4.4.2 Stack Pointer (SP)
The stack pointer (SP) is register R13. In Thread mode, the function of this register changes depending on
the ASP bit in the CONTROL register. When the ASP bit is clear, this register is the main stack pointer
(MSP). When the ASP bit is set, this register is the process stack pointer (PSP). On reset, the ASP bit is
clear, and the processor loads the MSP with the value from address 0x0000.0000. The MSP can only be
accessed in privileged mode; the PSP can be accessed in either privileged or unprivileged mode.
Figure 24-4. Stack Pointer Register (SP)
31
0
SP
R/W
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 24-4. Cortex General-Purpose Registers 0-12 (R0-R12) Field Descriptions
Bit
Field
Value
Description
31-0
SP
Stack pointer address