AN2430 Datasheet, PDF (17/24 Pages) STMicroelectronics – STR75x SystemMemory boot mode

AN2430
General description
1.5
Exiting SystemMemory boot mode
SystemMemory boot mode must be exited in order to execute a program in a normal User
mode. The STR75x may exit this mode by applying a hardware Reset. At the time of Reset,
the BOOT pins (BOOT0 and BOOT1) must be set at the proper levels to enter the desired
user mode. Following the Reset, the STR75x CPU begins executing code from location
0x00000000.
Table 4. Mode Pin vs. memory mapping
BOOT1 BOOT0
Boot Mode
Aliasing
0
0
Embedded Flash
Embedded Flash sector
B0F0 mapped at 0h
1
0
Embedded SRAM
Embedded SRAM mapped
at 0h
0
1
SystemMemory
SystemMemory mapped at
0h
1
1
External SMI
SMI bank 0 mapped at 0h
Note
All FLASH sectors
accessible except
SystemMemory sector
-
-
-
1.6
SystemMemory code program flow
Figure 11. SystemMemory code program flow
Start
Falling Edge on
No
UART0 Rx?
Start Timer Base
No
Falling Edge on
UART0 Rx ?
Stop Timer Base
Initialize UART0
Send Acknowledge
Clear the bit 22 of
the Flash Control
Register (Remap)
Done
Wait for a command
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