AN4253 Datasheet, PDF (31/44 Pages) STMicroelectronics – SPC564Lx device startup flow

AN4253
9
Application ‘asm’ startup
Application ‘asm’ startup
Before jumping to ‘C’ language to continue with the startup there are still some steps
required. These steps are completely under user or any other software vendor (i.e. OS
supplier) responsibility. Simply this ‘asm’ part shall prepare a base for the ‘C’ programming
environment.
Among usual steps belongs:
• Initialization of r1 register (link register)
• Initialization of r2 register (sdata2 base pointer)
• Initialization of r13 register (sdata base pointer)
• Stack initialization
• Initialization of initialized variables
DocID024255 Rev 2
31/44