19.1.4.14 Hardware and Software Constraints

The following table provides clock frequencies configured by the ROM code during boot.

Table 19-4. Clock Frequencies During External Memory Boot Sequence
Clock Frequency
SYSPLL 378 MHz
CPU_CLK / CPUPLL 570 MHz
MCK0 142 MHz
MCK1 189 MHz
MCK4 378 MHz
SDMMC (init/operational) 400 kHz / 25 MHz
SPI 47 MHz
QSPI 47 MHz

The NVM drivers use several PIOs in Peripheral mode to communicate with external memory devices. Care must be taken when these PIOs are used by the application. The connected devices could be unintentionally driven at boot time, and thus electrical conflicts between the output pins used by the NVM drivers and the connected devices could occur.

The following table contains a list of pins that are driven during the boot program execution. These pins are driven during the boot sequence for a period of less than 1 second if no correct boot program is found. The drive strength of pull-up I/O pins is set to low while the pins are used in Peripheral mode by the ROM code.

Before performing the jump to the application in the internal SRAM, all the PIOs and peripherals used in the boot program are set to their reset state.

Table 19-5. PIO Driven During Boot Program Execution
NVM Bootloader Peripheral IO Set Signal PIO Line Pull-up
SD Card/e.MMC SDMMC_0 1 SDMMC0_CK PIO_PA0A –
SDMMC0_CMD PIO_PA1A X
SDMMC0_DAT0 PIO_PA3A X
SDMMC0_DAT1 PIO_PA4A X
SDMMC0_DAT2 PIO_PA5A X
SDMMC0_DAT3 PIO_PA6A X
SDMMC_1 1 SDMMC1_CMD PIO_PB29A X
SDMMC1_CK PIO_PB30A –
SDMMC1_DAT0 PIO_PB31A X
SDMMC1_DAT1 PIO_PC0A X
SDMMC1_DAT2 PIO_PC1A X
SDMMC1_DAT3 PIO_PC2A X
SDMMC_2 1 SDMMC2_CMD PIO_PD3A X
SDMMC2_CK PIO_PD4A –
SDMMC2_DAT0 PIO_PD5A X
SDMMC2_DAT1 PIO_PD6A X
SDMMC2_DAT2 PIO_PD7A X
SDMMC2_DAT3 PIO_PD8A X
QSPI Flash QSPI_0 1 QIO3 PIO_PB9A X
QIO2 PIO_PB10A X
QIO1 PIO_PB11A X
QIO0 PIO_PB12A X
QCS PIO_PB13A –
QSCK PIO_PB14A –
QSCKN PIO_PB15A –
QIO4 PIO_PB16A X
QIO5 PIO_PB17A X
QIO6 PIO_PB18A X
QIO7 PIO_PB19A X
QSPI_1 1 QIO3 PIO_PB22A X
QIO2 PIO_PB23A X
QIO1 PIO_PB24A X
QIO0 PIO_PB25A X
QCS PIO_PB26A –
QSCK PIO_PB27A –
Console and Monitor FLEXCOM0_UART 1 DTXD PIO_PA0B –
DRXD PIO_PA1A X
FLEXCOM0_UART 2 DTXD PIO_PD3B –
DRXD PIO_PD4B X
FLEXCOM0_UART 3 DTXD PIO_PD10F –
DRXD PIO_PD11F X
FLEXCOM0_UART 4 DTXD PIO_PE3B –
DRXD PIO_PE4B X
FLEXCOM1_UART 1 DTXD PIO_PA5B –
DRXD PIO_PA6B X
FLEXCOM1_UART 2 DTXD PIO_PD12B –
DRXD PIO_PD13B X
FLEXCOM1_UART 3 DTXD PIO_PA2F –
DRXD PIO_PA3F X
FLEXCOM1_UART 4 DTXD PIO_PC9F –
DRXD PIO_PC10F X
FLEXCOM2_UART 1 DTXD PIO_PA7B –
DRXD PIO_PA8B X
FLEXCOM2_UART 2 DTXD PIO_PD17B –
DRXD PIO_PD18B X
FLEXCOM2_UART 3 DTXD PIO_PA4F –
DRXD PIO_PA5F X
FLEXCOM2_UART 4 DTXD PIO_PC11F –
DRXD PIO_PC12F X
FLEXCOM2_UART 5 DTXD PIO_PD14F –
DRXD PIO_PD15F X
FLEXCOM3_UART 1 DTXD PIO_PA15B –
DRXD PIO_PA16B X
FLEXCOM3_UART 2 DTXD PIO_PC0B –
DRXD PIO_PC1B X
FLEXCOM3_UART 3 DTXD PIO_PA6F –
DRXD PIO_PA7F X
FLEXCOM3_UART 4 DTXD PIO_PC13F –
DRXD PIO_PC14F X
FLEXCOM3_UART 5 DTXD PIO_PD16F –
DRXD PIO_PD17F X
FLEXCOM4_UART 1 DTXD PIO_PA20B –
DRXD PIO_PA21B X
FLEXCOM4_UART 2 DTXD PIO_PC2B –
DRXD PIO_PC3B X
FLEXCOM4_UART 3 DTXD PIO_PA8F –
DRXD PIO_PA9F X
FLEXCOM4_UART 4 DTXD PIO_PC15F –
DRXD PIO_PC16F X
FLEXCOM4_UART 5 DTXD PIO_PD18F –
DRXD PIO_PD19F X
Console and Monitor FLEXCOM5_UART 1 DTXD PIO_PA28B –
DRXD PIO_PA29B X
FLEXCOM5_UART 2 DTXD PIO_PD25B –
DRXD PIO_PD26B X
FLEXCOM5_UART 3 DTXD PIO_PA10F –
DRXD PIO_PA11F X
FLEXCOM5_UART 4 DTXD PIO_PC17F –
DRXD PIO_PC18F X
FLEXCOM5_UART 5 DTXD PIO_PD20F –
DRXD PIO_PD21F X
FLEXCOM6_UART 1 DTXD PIO_PB2B –
DRXD PIO_PB1B X
FLEXCOM6_UART 2 DTXD PIO_PD30B –
DRXD PIO_PD31B X
FLEXCOM6_UART 3 DTXD PIO_PA12F –
DRXD PIO_PA13F X
FLEXCOM6_UART 4 DTXD PIO_PC19F –
DRXD PIO_PC20F X
FLEXCOM6_UART 5 DTXD PIO_PC21F –
DRXD PIO_PC22F X
FLEXCOM7_UART 1 DTXD PIO_PB23B –
DRXD PIO_PB24B X
FLEXCOM7_UART 2 DTXD PIO_PC7B –
DRXD PIO_PC8B X
FLEXCOM7_UART 3 DTXD PIO_PA25F –
DRXD PIO_PA26F X
FLEXCOM7_UART 4 DTXD PIO_PB28F –
DRXD PIO_PB29F X
FLEXCOM7_UART 5 DTXD PIO_PC23F –
DRXD PIO_PC24F X
FLEXCOM8_UART 1 DTXD PIO_PB8B –
DRXD PIO_PB9B X
FLEXCOM8_UART 2 DTXD PIO_PC14B –
DRXD PIO_PC13B X
FLEXCOM8_UART 3 DTXD PIO_PA27F –
DRXD PIO_PA28F X
FLEXCOM8_UART 4 DTXD PIO_PB30F –
DRXD PIO_PB31F X
FLEXCOM8_UART 5 DTXD PIO_PD2F –
DRXD PIO_PD3F X
FLEXCOM9_UART 1 DTXD PIO_PB13B –
DRXD PIO_PB14B X
FLEXCOM9_UART 2 DTXD PIO_PC18B –
DRXD PIO_PC19B X
FLEXCOM9_UART 3 DTXD PIO_PA29F –
DRXD PIO_PA30F X
FLEXCOM9_UART 4 DTXD PIO_PC0F –
DRXD PIO_PC1F X
FLEXCOM9_UART 5 DTXD PIO_PD4F –
DRXD PIO_PD5F X
FLEXCOM10_UART 1 DTXD PIO_PB18B –
DRXD PIO_PB19B X
FLEXCOM10_UART 2 DTXD PIO_PC30B –
DRXD PIO_PC31B X
FLEXCOM10_UART 3 DTXD PIO_PA31F –
DRXD PIO_PB0F X
FLEXCOM10_UART 4 DTXD PIO_PC2F –
DRXD PIO_PC3F X
FLEXCOM10_UART 5 DTXD PIO_PC6F –
DRXD PIO_PC7F X
FLEXCOM11_UART 1 DTXD PIO_PB3B –
DRXD PIO_PB4B X
FLEXCOM11_UART 2 DTXD PIO_PD0B –
DRXD PIO_PD1B X
FLEXCOM11_UART 3 DTXD PIO_PB1F –
DRXD PIO_PB2F X
FLEXCOM11_UART 4 DTXD PIO_PC4F –
DRXD PIO_PC5F X
FLEXCOM11_UART 5 DTXD PIO_PD8F –
DRXD PIO_PD9F X