SPRUJ79 November 2024 F29H850TU , F29H859TU-Q1
The purpose of this chapter is to explain the boot read-only memory (ROM) code functionality for the C29x CPU core's, including the boot procedure. This chapter also discusses the functions and features of the boot ROM code, and provides details about the ROM memory-map contents. On every reset, the device executes a boot sequence in the ROM depending on the reset type and boot configuration. This sequence initializes the device to run the application code. For the CPU, the boot ROM also contains peripheral bootloaders that can be used to load an application into RAM. These bootloaders can be disabled for safety or security purposes.
See Table 4-1 for details on available boot features for the C29x CPU. Additionally, Table 4-2 shows the sizes of the various ROMs on the device.
Various tables are provided in ROM for use in software library, refer to Section 4.7.5 for more details.
| Boot Feature | CPU |
|---|---|
| Initial boot process | Device reset |
| Boot mode selection | GPIOs |
| Boot modes supported |
Flash boot RAM boot Wait boot Parallel IO CAN CAN-FD I2C SPI UART |
| ROM | Size |
|---|---|
| CPU1 boot ROM | 128KB |
| CPU2 boot ROM | 32KB |
| CPU3 boot ROM | 32KB |
CPU2 and CPU3 doesn't have any BootROM code and just contains default NMI handler. During initialization application needs to re-assign the handler to override the default handler. CPU2/3 default NMI handlers points to infinite while loop. This section further explains in detail on the CPU1 Boot ROM flow.