Flexbus SRAM access on MKV58F1M0VLQ24 without excluding stock KBOOT

[JulianS]

Hello,

I am working with the MKV58F1M0VLQ24 microcontroller on a custom PCB design and ran into problems with the possible pin multiplexing on this chip.

At first, for our project I need the stock KBOOT bootloader that is flashed to the device from NXP during the manufacturing process. In our initial operation, we want to use the kinetis flash tool with the KBOOT on the chip in order to flash our own application. Taken this as a basis, we are forced to use the UART0_RX on PTD6 of the µC, as well as PTD7 for UART0_TX.

Because we ran out of ram in the previous hardware version, we want to use an external SRAM via the flexbus interface. This forces us to use several µC pins that are available for the usage of the flexbus interface. One of them is the FB_AD0 feature, which can only be configured on PTD6 of the µC.

So my question here is: Is there any chance to use the "full" flexbus interface (or in that case especially the FB_AD0) in my own application, if I also want to use the stock KBOOT on the µC for the initial operation?

Kind Regards,

Julian

[Omar_Anguiano]

Hello

You can use the PTD6 in UART mode while loading your application and then use the same pin for Flex Bus during the execution of your application.

Let me know if this is helpful, if you have more questions do not hesitate to ask me.

Best regards,

Omar

[JulianS]

Hello Omar,

that's the point, I want to use UART and the FlexBus at once... even in my application. I only have one UART-Port on my pcb to performe the initial flashing via KBOOT as well as using it for my own application uart. As far as I can see, the µC can't really handle this problem without adapting the pcb environment. I think I'll need to implement a hardware analog switch to fullfill my needs.

Thank you for your reply.

Kind regards,

Julian