Atmel SAM4S Xplained Pro Starter Kit Atmel ATSAM4S-XSTK ATSAM4S-XSTK Data Sheet
Product codes
ATSAM4S-XSTK
51
SAM4S [DATASHEET]
11100E–ATARM–24-Jul-13
12.4.1.4 General-purpose Registers
R0-R12 are 32-bit general-purpose registers for data operations.
12.4.1.5 Stack Pointer
The Stack Pointer (SP) is register R13. In Thread mode, bit[1] of the CONTROL register indicates the stack pointer to
use:
use:
0 = Main Stack Pointer (MSP). This is the reset value.
1 = Process Stack Pointer (PSP).
On reset, the processor loads the MSP with the value from address 0x00000000.
12.4.1.6 Link Register
The Link Register (LR) is register R14. It stores the return information for subroutines, function calls, and exceptions. On
reset, the processor loads the LR value 0xFFFFFFFF
reset, the processor loads the LR value 0xFFFFFFFF
.
12.4.1.7 Program Counter
The Program Counter (PC) is register R15. It contains the current program address. On reset, the processor loads the
PC with the value of the reset vector, which is at address 0x00000004. Bit[0] of the value is loaded into the EPSR T-bit at
reset and must be 1.
PC with the value of the reset vector, which is at address 0x00000004. Bit[0] of the value is loaded into the EPSR T-bit at
reset and must be 1.