SPRSPB9B July 2025 – October 2025 F28E120SB , F28E120SC
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
This section explains the default boot modes, as well as all the available boot modes supported on this device. The boot ROM uses the boot mode select, general-purpose input/output (GPIO) pins to determine the boot mode configuration.
Table 7-5 shows the boot mode options available for selection by the default boot mode select pins. Users have the option to program the device to customize the boot modes selectable in the boot-up table as well as the boot mode select pin GPIOs used.
All the peripheral boot modes that are supported use the first instance of the peripheral module (SCIA, SPIA, I2CA, and so forth). Whenever these boot modes are referred to in this chapter, such as SCI boot, it is actually referring to the first module instance, which means the SCI boot on the SCIA port. The same applies to the other peripheral boots.
See the Reset (XRSn) Switching Characteristics table and the Reset Timing Diagrams section for tboot-flash, the boot ROM execution time to first instruction fetch in flash.
| BOOT MODE | GPIO24 (DEFAULT BOOT MODE SELECT PIN 1) |
GPIO32 (DEFAULT BOOT MODE SELECT PIN 0) |
|---|---|---|
| Parallel IO | 0 | 0 |
| SCI / Wait Boot(1) | 0 | 1 |
| Flash | 1 | 1 |
Table 7-6 lists the possible boot modes supported on the device. The default boot mode pins are GPIO24 (boot mode pin 1) and GPIO32 (boot mode pin 0). Users may choose to have weak pullups for boot mode pins if they use a peripheral on these pins as well, so the pullups can be overdriven. On this device, customers can change the factory default boot mode pins by programming user-configurable Dual Code Security Module (DCSM) OTP locations.
| BOOT MODE NUMBER | BOOT MODE |
|---|---|
| 0 | Parallel |
| 1 | SCI / Wait |
| 3 | Flash |
| 4 | Wait |
| 5 | RAM |
| 6 | SPI |
| 7 | I2C |
| 10 | Secure Flash |