ST STM32F10 Series, Application Note

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AN2586 - Application note Boot configuration
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3 Boot configuration
3.1 Boot mode selection
In the STM32F10xxx, three different boot modes can be selected by means of the
BOOT[1:0] pins as shown in
Table 1 .
This selection aliases the physical memory associated with each boot mode to Block 000
(boot memory). The values on the BOOT pins are latched on the 4
th
rising edge of SYSCLK
after a reset. It is up to the user to set the BOOT1 and BOOT0 pins after reset to select the
required boot mode.
The BOOT pins are also re-sampled when exiting the Standby mode. Consequently, they
must be kept in the required Boot mode configuration in the Standby mode.
Even when aliased in the boot memory space, the related memory (Flash memory or
SRAM) is still accessible at its original memory space.
After this startup delay has elapsed, the CPU starts code execution from the boot memory,
located at the bottom of the memory address space starting from 0x0000_0000.
3.2 Boot pin connection
Figure 11 shows the external connection required to select the boot memory of the
STM32F10xxx.
Figure 11. Boot mode selection implementation example
1. Resistor values are given only as a typical example.
Table 1. Boot modes
BOOT mode selection pins
Boot mode Aliasing
BOOT1 BOOT0
x 0
User Flash memory
User Flash memory is selected as boot
space
0 1
System memory
System memory is selected as boot
space
1 1
Embedded SRAM
Embedded SRAM is selected as boot
space
ai14373
V
DD
STM32F10xxx
BOOT0
BOOT1
V
DD
10 k
Ω
10 k
Ω