Datasheet

46
4337K–USB–04/08
AT89C5130A/31A-M
Figure 11-1. Flash Memory Mapping
11.2 Boot Process
11.2.1 Software Boot Process Example
Many algorithms can be used for the software boot process. Below are descriptions of the differ-
ent flags and Bytes.
Boot Loader Jump bit (BLJB):
- This bit indicates if on RESET the user wants to jump to this application at address @0000h on
FM0 or execute the boot loader at address @F400h on FM1.
- BLJB = 0 (i.e. bootloader FM1 executed after a reset) is the default Atmel factory programming.
-To read or modify this bit, the APIs are used.
Boot Vector Address (SBV):
- This byte contains the MSB of the user boot loader address in FM0.
- The default value of SBV is FFh (no user boot loader in FM0).
- To read or modify this byte, the APIs are used.
Extra Byte (EB) & Boot Status Byte (BSB):
- These Bytes are reserved for customer use.
- To read or modify these Bytes, the APIs are used.
F400h
7FFFh
32K Bytes
Flash Memory
3K Bytes IAP
Bootloader
FM0
FM1
Custom
Bootloader
[SBV]00h
FFFFh
FM1 Mapped between F400h and FFFFh
when API Called
0000h
3FFFh
16K Bytes
Flash Memory
FM0
Custom
Bootloader
[SBV]00h
0000h
C5130A C5131A