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Legacy microcontrollers

ryko_3280246
Level 1
5 questions asked First reply posted First question asked
Level 1

Hi,

I have a problem.

When I using a 4 MHz quartz oscillator, I entered to the internal bootloader with the INIT reset signal and sending the "V" symbol through the UART4, 9600 baud. This is good.

However, using a 12MHz oscillator and the same procedure, the internal bootloader does not respond. What's the problem, is the bootloader can't operate at 12 MHz?

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1 Solution
Praveen
Community Manager
Community Manager 250 sign-ins 100 sign-ins 50 replies posted
Community Manager

Hi Rysardas,

The bootloader for this product is fixed to 9600 baud rate for 4MHz crystal.

If the crystal frequency is increased to 12MHz, we assume that the UART baud rate should be 28800. You need to take care to increase the baud rate of the Flash programming tool. As I know, the Cypress tool is not supporting 12MHz.

Alternatively a synchronous UART communication can also be done. Find more information in the MB91460 TRM.

Here an abstract of this chapter:

trm.jpg

Be also sure that boot security is not activated, otherwise, the internal bootloader is skipped.

Cheers
Praveen

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1 Reply
Praveen
Community Manager
Community Manager 250 sign-ins 100 sign-ins 50 replies posted
Community Manager

Hi Rysardas,

The bootloader for this product is fixed to 9600 baud rate for 4MHz crystal.

If the crystal frequency is increased to 12MHz, we assume that the UART baud rate should be 28800. You need to take care to increase the baud rate of the Flash programming tool. As I know, the Cypress tool is not supporting 12MHz.

Alternatively a synchronous UART communication can also be done. Find more information in the MB91460 TRM.

Here an abstract of this chapter:

trm.jpg

Be also sure that boot security is not activated, otherwise, the internal bootloader is skipped.

Cheers
Praveen