TMS320F28P650DK: SCI pins confrimations when selecting Bootdef 0x01

Colombo Carlo

Mastermind 23395 points

Part Number: TMS320F28P650DK

Tool/software:

Hi Everybody ,

I want to boot and wait for SCI , I m in 256 BGA package

now BOOT DEF set to 0x01 ( wait on SCI ) , and so GPIO 12 and GPIO13 must be the TX and RX for SCI

now question : if I look to table 14-7 in TRM ( latest on web ) "GPIO MUXED PINS" I Can see that at reset GPIO12 and 13 are EPWM7 a and b --> so HOW they can be SCI TX and RX for boot ?

i m expeting you need to enter and configure GPIOs before moving away to be ePWM

can you help me ?

thank you

BR
Carlo

9 months ago

+1 Allison Nguyen 9 months ago

TI__Mastermind 20880 points

Hi Carlo,

When the device boots up, it will look at the dedicated boot pins to determine which boot mode is selected. If you have set the boot pins to select SCI boot mode, then by default, the SCI bootloader routine will initialize these GPIOs as SCI pins and use them to load program to the device. If you do not use SCI boot mode, and instead (for example) boot to flash, the GPIOs will remain their default signal state as outlined in the GPIO muxing. The GPIOs can be initialized and used as EPWM pins as defined in your main().

If you are saying you want to try to choose different GPIOs for SCI booting, you can do this so that the non-default SCI boot pins are used. The options are as shown in the device's SCI bootloader as well as device's technical documentation: