C2000(TMS320F28335) Bootloader Design ?

Hi Kartal Kartal,

You can use the serial_flash_programmer which is a standalone tool included in C2000Ware to program flash for your device over UART. You will just need to make sure that the device is in the SCI bootmode before running the application. Here is a link to the app note that discusses using the serial_flash_programmer:

www.ti.com/.../sprabv4b.pdf

Table 2-2 in the TMS320x2833x, 2823x Boot ROM Reference Guide describes the GPIO combinations needed to select the desired boot mood. Information on Boot ROM in general is included in the following guide:

www.ti.com/.../spru963a.pdf

Thanks,
Taumer

Thank you for your answer.

I can understand that i should set and reset 4 pins to use SCI bootmode. But i can not see any information about JTAG bootmode. I have my own design PCB and i use there JTAG pins. Cause of that i want to use JTAG pins to reprogram TI processor. Are there any specific document about bootload with JTAG bootmode?

Regards.

Hi Kartal Kartal,

Are you using the XDS100 emulator? If so, you can program the F28335 through JTAG by using CCS or another similar program.

Thanks,
Taumer

Hi Taumer,
I designed my own bootloader. I don not use PC or a CCS etc program. My bootloader takes datas from SDcard and send them from UART(or which protocol what i want.) . I just wonder that what should i do before i send this data from JTAG pins to F28335's flash. I meant what is pin setting like F28335 GPIOx should be high, GPIOy should be low.

Thanks for help.

Kartal,

There is nothing like JTAG boot mode. Are you talking about Emulation boot mode which is applicable when JTAG is connected?

Also, how do you know whether device is connected through JTAG without CCS (or) PC? Which emulator are you using?

Regards,

Manoj

Hi Monaj,
My company is designing boards that use texas F28335 processors. Right now we use XDS100 and XDS110 emulator to program these boards. And i know that this emulator use JTAG pins to program processor. I designed my own bootlader and i am planing to reprogram these boards with this bootlader. If i can, i am gonna use JTAG pins to reprogram F28335 processor wtih my bootlader. But i don not know what should i do at first to reprogram F28335 processor. Cause that i asked " what is pin setting, like F28335's GPIOx should be high, GPIOy should be low. "

Regards,

Kartal.

Hi Kartal,

As Manoj said, there is no JTAG boot mode. Out of curiosity, why can't you set the device to be in SCI boot mode and program the device that way? Why are you attempting to program the flash through the JTAG pins?

Taumer

Hi Taumer,

We use processsor's other pins on board. If i use SCI boot pins(like UART or CAN or etc) i should do rework for product boards. So JTAG pins will be better for me if i could use. But if JTAG method is too hard to design bootloader i am gonna use SCI modes.

Regards.

Hi Kartal,

I think using the SCI boot mode is the best option here.

Thanks,
Taumer

Hi Taumer,
There is not anyway to desgin a bootlader which uses TJAG mode?

Thanks.

Hi Kadir,
I use another processor to load image file to Texas processor's flash. But i should choose a way that SCI or JTAG mode. And i do not know what must i do before starting to send data to TMS320F28335's flash with JTAG pins.

Regards,

If you choose to use SCI, then you should write a bootloader application on F28335, which initializes the corresponding SCI channel, communicates with your other processor, gets the image from SCI and writes it to the flash of F28335. The bootloader should run on the startup and wait for data from SCI. If there is no data (after some time), the bootloader should jump to the application in the flash of F28335. As Taumer said, you can use these documents as a guide.

www.ti.com/.../sprabv4b.pdf
www.ti.com/.../spru963a.pdf


I dont know a lot about the JTAG mode. But as far as I know, If you choose to program your F28335 with JTAG, you should have a JTAG and a PC to program the flash of F28335.

Regards

Hi Kadir,
I can not understand why should i program target processor. So for your suggestion i can not program flash of an empty processor. And i should write program transmitter and target processor both of them?

Regards.

Hi Kartal,

I believe Kadir is referring to the concept of a flash kernel, which is described in the following document:

www.ti.com/.../sprabv4b.pdf

Essentially, you will need a custom bootloader running on the F28335 that accepts the program via SCI and programs the flash using FLASH API commands. There is an example of a f28335_flash_kernel included in C2000Ware.

Thanks,
Taumer