Hi Jorge,
Thanks for looking into this.
Both MCU not having the same application.
Below will be the sequence to upgrade firmware.
1-) First Host will send command to MCU2(KL26) for upgrade firmware and upgrade it.
2-) Then Host will send another command via MCU2(KL26) to upgrade firmware for MCU1(KL25) and it is not compulsory to upgrade every time but some time needed.
Its bit urgent for me and let me know if more inputs required.
Regards,
Sunil