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AM2434: Tamagawa Cycle Time

Kevin Peng
Expert 3802 points
Part Number: AM2434
Other Parts Discussed in Thread: SYSCONFIG

Tool/software:

Hi TI Experts,

Customer is working on AM243x SDK9.2.

They have built the Tamagawa project, and the Tamagawa PRU-ICSS firmware is loaded and running successfully.

As you could see below, there is an option 9 to configure the IEP reset cycle count & IEP trigger time.

|------------------------------------------------------------------------------|
| Select DATA ID Code |
|------------------------------------------------------------------------------|
| 0 : Data readout, Absolute (Data ID 0) |
| 1 : Data readout, Multi-turn (Data ID 1) |
| 2 : Data readout, Encoder-ID (Data ID 2) |
| 3 : Data readout, Absolute & Multi-turn (Data ID 3) |
| 4 : Writing to EEPROM (Data ID 6) |
| 5 : Reset (Data ID 7) |
| 6 : Reset (Data ID 8) |
| 7 : Reset (Data ID C) |
| 8 : Readout from EEPROM (Data ID D) |
| 9 : Start periodic continuous mode |
|------------------------------------------------------------------------------|
|

| enter value: 9
| Enter IEP reset cycle count (must be greater than Tamagawa cycle time including timeout period, in IEP cycles):
| Enter IEP trigger time(must be less than or equal to IEP reset cycle, in IEP cycles): 

Customer has the following 2 questions regarding to the configuration of the cycle time in option 9 above.

1: What is the unit of the IEP cycle? (for example, is it in microsecond us or millisecond ms or nanosecond ns)

2: Customer has tried enter the IEP trigger time to 50, but the result is only refreshed 1 time, not being continuously refreshed. Customer wants to know the reason why only 1 time the result is refreshed?

Could you help please provide some feedback for the above 2 questions please?

Thanks,

Kevin

  • 0
    TI__Expert 3802 points

    Hi TI Experts,

    Customer has done an experiment, and please analyze their results, thanks!

    Customer has tried setting IEP cycle to 12000, and using oscilloscope measured the period is about 90us, so the corresponding frequency is about 12000 / 90 = 133MHz.

    Could you please confirm this?

    Thanks,

    Kevin

  • +1
    TI__Intellectual 2730 points

    Hi Kevin,

    Kevin Peng said:
    What is the unit of the IEP cycle? (for example, is it in microsecond us or millisecond ms or nanosecond ns)

    This is the IEP count which increases by 1 after every IEP clock cycle. If the IEP is running at 200 MHz, it will increase by 1 after every 5ns.

    Please see below the attached image which shows the IEP rest cycle and the trigger point.

    You can configure the IEP Rest count based on the Tamagawa cycle time, it should always be greater than Tamagawa cycle time.

    And for the trigger time you have to configure the trigger count between 0 and IEP rest count.

    BR,

    Achala Ram

  • 0 in reply to Kevin Peng
    TI__Intellectual 2730 points
    Kevin Peng said:

    Customer has tried setting IEP cycle to 12000, and using oscilloscope measured the period is about 90us, so the corresponding frequency is about 12000 / 90 = 133MHz.

    Could you please confirm this?

    No, this value should be equal to the configured IEP clock value.

  • 0 in reply to Achala Ram
    TI__Expert 3802 points

    Hi Achala,

    Thanks for your reply with details!

    And we also know that the IEP frequency is configured in the sysconfig shown below.

    Thanks,

    Kevin