This section details what boot
configurations are available and how to configure them. This device supports from
zero boot mode select pins up to three boot mode select pins and from one configured
boot mode up to eight configured boot modes.
To change and configure the device
from the default settings to custom settings for your application, use the following
process:
- Determine all the various ways you want application to be able
to boot. (For example: Primary boot option of Flash boot for your main
application, secondary boot option of SPI for firmware updates, tertiary boot
option of SCI boot for debugging, and so forth.)
- Based on the number of boot modes needed, determine how many
boot mode select pins (BMSPs) are required to select between your selected boot
modes. (For example: Two BMSPs are required to select between three boot mode
options)
- Assign the required BMSPs to a physical GPIO pin. (For example,
BMSP0 to GPIO10, BMSP1 to GPIO51, and BMSP2 left as default which is disabled).
Refer to Section 7.6.1.1 for all the details on performing these configurations.
- Assign the determined boot mode definitions to indexes in your
custom boot table that correlate to the decoded value of the BMSPs. For example,
BOOTDEF0=Boot to Flash, BOOTDEF1=SPI Boot, BOOTDEF2=SCI Boot; all other BOOTDEFx
are left as default/nothing). Refer to the Configuring Boot Mode Pins
section for all the details on setting up and configuring the custom boot mode
table.
Additionally, the Boot Mode Example
Use Cases section of the F28E12x Real-Time Microcontrollers
Technical Reference Manual provides some example use cases on how
to configure the BMSPs and custom boot tables.