TMS320F28027 XRS PIN Toggle

tariq saeed1

Other Parts Discussed in Thread: TMS320F28027

hi,

i am facing issue related to XRS pin on TMS320F28027 CPU, once i program the target and RUN the program , it work OK , but if i power recycle the CPU then the problem arises i.e. XRS pin toggles with a fix interval.

when i connect jtag again with the target cpu , the XRS toggling stops.

i am using example code provided by TI

regards

Tariq

over 11 years ago

0 Gautam Iyer over 11 years ago

Guru 192875 points

Hi Tariq,

Is this a development board ie C2000 launchpad or a custom board? I guess its a custom board as you're using external jtag emulator, right? If so did you cross-verify the launchpad schematics with yours esp. around JTAG & XRS pins?

Regards,

Gautam

0 Adam Dunhoft over 11 years ago in reply to Gautam Iyer

TI__Expert 7885 points

Hi Tariq,

If you are programming to Flash, make sure that your boot pins are configured correctly.

Regards,

Adam

0 tariq saeed1 over 11 years ago in reply to Gautam Iyer

Prodigy 40 points

Hi gautam,

It is customboard and I have verified schematics thoroughly, infact there is no JTAG connectivity error, I can run the program and debug it as well, the issue come after this when power of target board is recycled , XRS pin goes in to toggle mode with fixed frequency.

Regards

Tariq

0 tariq saeed1 over 11 years ago in reply to Adam Dunhoft

Prodigy 40 points

Hi Adam,

Are you referring to TRST and TDO pins. As I have pulled down TRST pin and pulled up TDO pin in schematics with 2.2k. Is there any other pin?

Regards

Tariq

0 Adam Dunhoft over 11 years ago in reply to tariq saeed1

TI__Expert 7885 points

Hi Tariq,

You can find boot mode details in section 3.2.8 of the DS.

GPIO34 is also required.

Regards,

Adam

0 Ashutosh Pailwan1 over 9 years ago

Expert 2480 points

why it was toggling as I am also getting same thing..

0 Vivek Singh over 9 years ago in reply to Ashutosh Pailwan1

TI__Guru** 115881 points

If you set the BOOTPIN to boot from Flash (GetMode defaults to boot from Flash) and Flash is not programmed then CPU will fetch 0xFFFF_FFFF from Flash which is ITRAP. ITRAP handler in BOOTROM enables the watchdog to reset the device hence you see XRSn pin toggling.

Regards,
Vivek Singh

C2000™︎ microcontrollers

C2000 microcontrollers forum

TMS320F28027 XRS PIN Toggle