2.9.1.4.14 Hardware and Software Constraints

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

Table 2-22. 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 2-23. 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	–
	FLEXCOM0_UART	1	DRXD	PIO_PA1A	X
	FLEXCOM0_UART	2	DTXD	PIO_PD3B	–
	FLEXCOM0_UART	2	DRXD	PIO_PD4B	X
	FLEXCOM0_UART	3	DTXD	PIO_PD10F	–
	FLEXCOM0_UART	3	DRXD	PIO_PD11F	X
	FLEXCOM0_UART	4	DTXD	PIO_PE3B	–
	FLEXCOM0_UART	4	DRXD	PIO_PE4B	X
	FLEXCOM1_UART	1	DTXD	PIO_PA5B	–
	FLEXCOM1_UART	1	DRXD	PIO_PA6B	X
	FLEXCOM1_UART	2	DTXD	PIO_PD12B	–
	FLEXCOM1_UART	2	DRXD	PIO_PD13B	X
	FLEXCOM1_UART	3	DTXD	PIO_PA2F	–
	FLEXCOM1_UART	3	DRXD	PIO_PA3F	X
	FLEXCOM1_UART	4	DTXD	PIO_PC9F	–
	FLEXCOM1_UART	4	DRXD	PIO_PC10F	X
	FLEXCOM2_UART	1	DTXD	PIO_PA7B	–
	FLEXCOM2_UART	1	DRXD	PIO_PA8B	X
	FLEXCOM2_UART	2	DTXD	PIO_PD17B	–
	FLEXCOM2_UART	2	DRXD	PIO_PD18B	X
	FLEXCOM2_UART	3	DTXD	PIO_PA4F	–
	FLEXCOM2_UART	3	DRXD	PIO_PA5F	X
	FLEXCOM2_UART	4	DTXD	PIO_PC11F	–
	FLEXCOM2_UART	4	DRXD	PIO_PC12F	X
	FLEXCOM2_UART	5	DTXD	PIO_PD14F	–
	FLEXCOM2_UART	5	DRXD	PIO_PD15F	X
	FLEXCOM3_UART	1	DTXD	PIO_PA15B	–
	FLEXCOM3_UART	1	DRXD	PIO_PA16B	X
	FLEXCOM3_UART	2	DTXD	PIO_PC0B	–
	FLEXCOM3_UART	2	DRXD	PIO_PC1B	X
	FLEXCOM3_UART	3	DTXD	PIO_PA6F	–
	FLEXCOM3_UART	3	DRXD	PIO_PA7F	X
	FLEXCOM3_UART	4	DTXD	PIO_PC13F	–
	FLEXCOM3_UART	4	DRXD	PIO_PC14F	X
	FLEXCOM3_UART	5	DTXD	PIO_PD16F	–
	FLEXCOM3_UART	5	DRXD	PIO_PD17F	X
	FLEXCOM4_UART	1	DTXD	PIO_PA20B	–
	FLEXCOM4_UART	1	DRXD	PIO_PA21B	X
	FLEXCOM4_UART	2	DTXD	PIO_PC2B	–
	FLEXCOM4_UART	2	DRXD	PIO_PC3B	X
	FLEXCOM4_UART	3	DTXD	PIO_PA8F	–
	FLEXCOM4_UART	3	DRXD	PIO_PA9F	X
	FLEXCOM4_UART	4	DTXD	PIO_PC15F	–
	FLEXCOM4_UART	4	DRXD	PIO_PC16F	X
	FLEXCOM4_UART	5	DTXD	PIO_PD18F	–
	FLEXCOM4_UART	5	DRXD	PIO_PD19F	X
Console and Monitor	FLEXCOM5_UART	1	DTXD	PIO_PA28B	–
	FLEXCOM5_UART	1	DRXD	PIO_PA29B	X
	FLEXCOM5_UART	2	DTXD	PIO_PD25B	–
	FLEXCOM5_UART	2	DRXD	PIO_PD26B	X
	FLEXCOM5_UART	3	DTXD	PIO_PA10F	–
	FLEXCOM5_UART	3	DRXD	PIO_PA11F	X
	FLEXCOM5_UART	4	DTXD	PIO_PC17F	–
	FLEXCOM5_UART	4	DRXD	PIO_PC18F	X
	FLEXCOM5_UART	5	DTXD	PIO_PD20F	–
	FLEXCOM5_UART	5	DRXD	PIO_PD21F	X
	FLEXCOM6_UART	1	DTXD	PIO_PB2B	–
	FLEXCOM6_UART	1	DRXD	PIO_PB1B	X
	FLEXCOM6_UART	2	DTXD	PIO_PD30B	–
	FLEXCOM6_UART	2	DRXD	PIO_PD31B	X
	FLEXCOM6_UART	3	DTXD	PIO_PA12F	–
	FLEXCOM6_UART	3	DRXD	PIO_PA13F	X
	FLEXCOM6_UART	4	DTXD	PIO_PC19F	–
	FLEXCOM6_UART	4	DRXD	PIO_PC20F	X
	FLEXCOM6_UART	5	DTXD	PIO_PC21F	–
	FLEXCOM6_UART	5	DRXD	PIO_PC22F	X
	FLEXCOM7_UART	1	DTXD	PIO_PB23B	–
	FLEXCOM7_UART	1	DRXD	PIO_PB24B	X
	FLEXCOM7_UART	2	DTXD	PIO_PC7B	–
	FLEXCOM7_UART	2	DRXD	PIO_PC8B	X
	FLEXCOM7_UART	3	DTXD	PIO_PA25F	–
	FLEXCOM7_UART	3	DRXD	PIO_PA26F	X
	FLEXCOM7_UART	4	DTXD	PIO_PB28F	–
	FLEXCOM7_UART	4	DRXD	PIO_PB29F	X
	FLEXCOM7_UART	5	DTXD	PIO_PC23F	–
	FLEXCOM7_UART	5	DRXD	PIO_PC24F	X
	FLEXCOM8_UART	1	DTXD	PIO_PB8B	–
	FLEXCOM8_UART	1	DRXD	PIO_PB9B	X
	FLEXCOM8_UART	2	DTXD	PIO_PC14B	–
	FLEXCOM8_UART	2	DRXD	PIO_PC13B	X
	FLEXCOM8_UART	3	DTXD	PIO_PA27F	–
	FLEXCOM8_UART	3	DRXD	PIO_PA28F	X
	FLEXCOM8_UART	4	DTXD	PIO_PB30F	–
	FLEXCOM8_UART	4	DRXD	PIO_PB31F	X
	FLEXCOM8_UART	5	DTXD	PIO_PD2F	–
	FLEXCOM8_UART	5	DRXD	PIO_PD3F	X
	FLEXCOM9_UART	1	DTXD	PIO_PB13B	–
	FLEXCOM9_UART	1	DRXD	PIO_PB14B	X
	FLEXCOM9_UART	2	DTXD	PIO_PC18B	–
	FLEXCOM9_UART	2	DRXD	PIO_PC19B	X
	FLEXCOM9_UART	3	DTXD	PIO_PA29F	–
	FLEXCOM9_UART	3	DRXD	PIO_PA30F	X
	FLEXCOM9_UART	4	DTXD	PIO_PC0F	–
	FLEXCOM9_UART	4	DRXD	PIO_PC1F	X
	FLEXCOM9_UART	5	DTXD	PIO_PD4F	–
	FLEXCOM9_UART	5	DRXD	PIO_PD5F	X
	FLEXCOM10_UART	1	DTXD	PIO_PB18B	–
	FLEXCOM10_UART	1	DRXD	PIO_PB19B	X
	FLEXCOM10_UART	2	DTXD	PIO_PC30B	–
	FLEXCOM10_UART	2	DRXD	PIO_PC31B	X
	FLEXCOM10_UART	3	DTXD	PIO_PA31F	–
	FLEXCOM10_UART	3	DRXD	PIO_PB0F	X
	FLEXCOM10_UART	4	DTXD	PIO_PC2F	–
	FLEXCOM10_UART	4	DRXD	PIO_PC3F	X
	FLEXCOM10_UART	5	DTXD	PIO_PC6F	–
	FLEXCOM10_UART	5	DRXD	PIO_PC7F	X
	FLEXCOM11_UART	1	DTXD	PIO_PB3B	–
	FLEXCOM11_UART	1	DRXD	PIO_PB4B	X
	FLEXCOM11_UART	2	DTXD	PIO_PD0B	–
	FLEXCOM11_UART	2	DRXD	PIO_PD1B	X
	FLEXCOM11_UART	3	DTXD	PIO_PB1F	–
	FLEXCOM11_UART	3	DRXD	PIO_PB2F	X
	FLEXCOM11_UART	4	DTXD	PIO_PC4F	–
	FLEXCOM11_UART	4	DRXD	PIO_PC5F	X
	FLEXCOM11_UART	5	DTXD	PIO_PD8F	–
	FLEXCOM11_UART	5	DRXD	PIO_PD9F	X