• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 80 subscribers
  • Views 861 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Is 1.8V sufficient to load program, or must be 2.2V?

John Mielke
Prodigy 230 points

Hi,

We have a custom board on which the regulator supplies stable 1.8V voltage to MPS430G2302. Using MSP-FET430UIF with 2-wire connection as shown in http://processors.wiki.ti.com/index.php/JTAG_(MSP430), we were able to connect to the device.

We had programs when loading .out file and encountered

error said:

MSP430: Trouble Writing Memory Block at 0xf000 on Page 0 of Length 0x92: Could not erase device memory

. When this happens we used MSP-FET430UIF JTAG pin 4 (VCC TARGET) to sense the board voltage level.

We suspected the error might have related to the 1.8V voltage and used external power supply of 2.2V, after that the connection was successful.  If we adjust the external voltage to below 2.2V, say 2.1 or 2.0, the loading error happens again despite successful connection.

The question is on the voltage. Datasheet SLAS723F MSP430G2x32, MSP430G2x02 Mixed Signal Microcontroller gives VCC [1.8, 3.6V] on p17 “Recommended Operating Conditions”. Though for flash programming/erase the lowest voltage is 2.2V, we were actually not doing any operation on the flash, just loading code and data to the ordinary memory. There are also other parts on the board designed for 1.8V operation and when using the external power supply we have to cut all of them off to avoid damage, so 1.8V is certainly preferred if it can also be to download code and data.

Could anyone tell us why even if we are not loading anything to flash memory we still need 2.2V voltage?

 

John

  • 0
    Guru 92251 points

    John Mielke said:
    Could anyone tell us why even if we are not loading anything to flash memory we still need 2.2V voltage?

    Due to the small amount of ram in MSP430 devices, when you create a program the code is placed in flash by the linker, and so when downloading a .out file in CCS the flash has to be erased and programmed to load the program.

    It may be possible to locate some in ram but the reset vector is in flash so don't think there is any way to eliminate the need for the target voltage to support flash operations when downloading from CCS.

  • 0 in reply to Chester Gillon
    Prodigy 230 points

    Chester,

    Understand it, thanks for the answer.

    John

  • 0
    Guru 227245 points

    John Mielke said:
    we were actually not doing any operation on the flash, just loading code and data to the ordinary memory.

    Well, the code is storeed in flash and runs from flash. Code in ram (the only other memory) would be gone as soon as the power supply fails. So to ahve the MSP doing anything at all, you'll at least once have to write to flash, which needs 2.2V at theis moment.

    John Mielke said:
    Could anyone tell us why even if we are not loading anything to flash memory we still need 2.2V voltage?

    To run a program that's stored on flash, you don't need 2.2V. Reading flash is possible from 1.8V on.

    However, to be able to write the code into the MSP, you'll need 2.2V at least during the programming cycle. So you need some way to provide 2.2V to the MSP while you are putting the code onto it (without frying your other circuitry). Or you program the MSP outside the PCB before soldering it.

**Attention** This is a public forum