Data displayed by oscilloscope is intermittent

[wbj5238]

   As shown in the figure below, I use freemaster's oscilloscope to observe intermittent data.I want to know what's the cause.

   We are looking forward to your favourable reply with keen interest.

   Thanks.

[MichalH]

Dear wang bingjian,

can you tell more about your setup: what is your target MCU and how is it connected to the computer? It seems the communication is unstable - In case of Serial or CAN connection, this might be caused by bad handling of communication events or too busy main loop. Enabling one of the interrupt modes could help.

Thanks,

Michal

[wbj5238]

My target MCU is mpc5744. It is connected to the computer by Prolific USB-to-Serial Comm Port. How should I use interrupt mode.

[MichalH]

The FreeMASTER driver uses freemaster_cfg.h to configure various options. User manual for the latest driver version can be found here. Most of the config options are valid even if you use an older driver version.

The interrupt mode can be enabled by setting FMSTR_SHORT_INTR or FMSTR_LONG_INTR options to 1 (and resetting FMSTR_POLL_DRIVEN to 0). You will also need to enable and handle the interrupt and call the FMSTR_SerialIsr function from your ISR (FMSTR_Isr in older version).

Regards,

Michal

[MichalH]

Dear wang bingjian,

did the interrupt mode help to resolve your issue?

Thanks,

Michal