RL78/L13 Problem with the clock speed

Hi, I designed a circuit with the RL78/L13 and created a prototype, but there is a problem. 

First I used the starter kit, added a different display without controller and programmed it myself.

It ran OK, so I decided to make a professional device, but problems came, the display doesn't work properly, I think the clock is the problem but I can't identify the configuration I have to change.

The difference is, the starter kit uses 2 clocks, the main(20MHz) and the subsystem(32,786KHz), but my device uses only the subsystem, and as the High Speed clock I'm usin the internal clock(24MHz). 

The display doesn't blink, it does only wuhen I change the program to blink some few segments, but when I use the library created about myself wich runs in the starter kit doesn't work. It seems that needs too much time changing the segments, so, you can't see any number.

Any idea?

Thank you

Sorry my english.

  • Hello earitz,

    Is your board the same as the circuit around the LCD of the Kit?
    Such as VL1,2,3,4 pins , COMx , SEGx and the voltage of VDD power supply.

  • In reply to Kirin:

    Sorry, I forgot.

    The LCD part is exactly the same, the capacitor split method, with 4 COM and 27 SEG.

    Refering the voltage(VDD) i'm trying different levels, but with 3,7v the LCD has the best contrast, but I can see only few segments.

    With more voltage I see the same but with all segments saturated.

    Thanks Kirin.



    I made a prgram wich waits 5000 ms(5 seconds) until changing a digital output from low to high and other 5 seconds to change from high to low.

    But with an oscilloscope I can see that the 5 seconds are converted in 300ms, less than a half of a second, I don't understand anything. It seems to run much faster, but It doesn't make any sense.

  • In reply to earitz:

    Hello earitz,

    Have you checked the LCD waveform?

  • In reply to Kirin:

    I have configured the A waveform, but the truth is that I have no idea what does it mean.

    Please check the EDITED comment wrote before.

    Thank you

  • In reply to earitz:

    Hello earitz,

    Umm, What value are SFR HOCODIV , SFR LCDC0 and OPTION-BYTE 0xC2?