Bootloader for TMS320F28335

Suvajit Mukherjee

Other Parts Discussed in Thread: TMS320F28335

Hello,

Can anyone suggest how can I get the bootloader program for making the board (based on TMS320F28335) programmable through RS232.

What are the pre-requisites? I understand that there is a particular GPIO which is required.

Also where does this bootloader program loaded? Is it on chip or is it on a external EEPROM?

Please suggest.

best regards

over 13 years ago

0 Brett Larimore over 13 years ago

TI__Guru 57255 points

SM,

The bootloader is in the MCU's ROM. At reset, the MCU chooses which boot mode to use based on the value of a certain set of GPIO pins.

The process is outlined in the particular MCU's boot ROM guide:
(for F28335) http://www.ti.com/lit/spru963

For SCI (RS232) boot you will use GPIO28 & GPIO29

The following forum post (and the utilities listed inside) may be useful if you are looking to reprogram the device via RS232:
http://e2e.ti.com/support/microcontrollers/tms320c2000_32-bit_real-time_mcus/f/171/p/62370/228260.aspx

Thank you,
Brett

0 Suvajit Mukherjee over 13 years ago in reply to Brett Larimore

Prodigy 220 points

Hi Brett,

Thanks for your suggestions.

I am looking for some sample codes for bootloader which can be used, or some suggestions to write the bootloader program.

regards

0 Suvajit Mukherjee over 13 years ago in reply to Suvajit Mukherjee

Prodigy 220 points

Hello,

I am still waiting for a response for the above query.

Also can I do a bootloading in the eZDSP of 28335?

regards

0 Brett Larimore over 13 years ago in reply to Suvajit Mukherjee

TI__Guru 57255 points

SM,

Are you looking to boot from RS232 and then:
1) flash the device from RS232 datastream?
2) load code into RAM and run from RAM until power down. At that point the code would need to be loaded again?

Bootloading is possible on the eZDSP and the guide on how to do this is the Boot ROM guide that I linked previously:
(for F28335) http://www.ti.com/lit/spru963
Figure 2-3 is what happens when the chip is reset and shows when the SCI boot loader is called.
Section 2.17 in part describes the SCI (RS232) boot loader.

Thank you,
Brett

0 Mark Lazarewicz over 12 years ago in reply to Brett Larimore

Expert 1505 points

If you dont want to use the TI BOOTROM bootloader I suggest looking at the BOOTROM source code project as an example of how a to write your own bootloader and then combine the FLASH_API example, if your intent i sto load your code into internal flash.

If you load into RAM the BOOTROM source code project project is a better reference but none of this is necessary unless the provided BOOTROM loader is not sufficient.

in my case I needed to load over CAN and the clock settings in the BOOTROM were to slow to meet our system start up time and I need to laod and run from internal flash

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Bootloader for TMS320F28335