• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 40 subscribers
  • Views 284 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.

TIDA-00161: Refresh rate of LED module

Michael Brandmaier
Prodigy 160 points
Part Number: TIDA-00161


Tool/software:

Hi all,

I currently want to understand the test results of TIDA-00161. The visual refresh rate of 3.5kHz is clear so far (33 MHz / 32 / 257) with 1 us pause each results in approx. 3.5 kHz.
The refresh rate of 60 Hz with an SPI of 6 MHz is also clear so far.
What I don't understand is why the refresh rate is not reduced, as one complete cycle for the grayscale clock results in approx. 16 Hz (3.5 kHz / 256 cycles).
How does a refresh rate of 60 Hz come about, or how does a grayscale with 14 bit come about?

Can anyone help me here?

Many thanks!

  • 0
    TI__Mastermind 32665 points

    Hi, Michael

    Our expert will reply you late.

  • 0
    TI__Expert 4471 points

    Hi Michael,

    1. The frame rate is 60, it's decided at first.

    2. One frame period has many visual-fresh periods. In each visual-fresh period, there are 32 scan segments. For 8+8 mode, each segment has 256 GCLK. In each channel's segment, 256 GCLKs can achieve 8bit greyscale.

    3. One frame period (16.67ms) has 59.47 visual-fresh period, which means every channel will have 59.47x256 GCLK to display a greyscale. Hence it can achieve 8+log(59.47, 2) = 13.89 bit greyscale. This is where 14 bit comes from.

    Best Regards,

    Suchen Dong