Controlling TLC5940 with MSP430G2553 doesn't work

[RobG 1,892]

Do I need to update DC register before updating GS register? Also, do I need the first cycle flag when not updating it?

No, unless you have changed DC values in EEPROM. Which flag are you referring to? With VPRG and DCPRG grounded, all you need to do is send GS data. You can read status register to see if everything is OK.

[pillum 0]

The first cycle flag. According to the Programing Flowchart you need to pulse SCLK the first time you updated GS data.

[RobG 1,892]

I am guessing you are referring to SCLK #193. According to spec sheet, you need it only once after DC cycle. However, not all charts support this statement. There seems to be discrepancy (figure 11 & 13 show this extra pulse after each GS cycle.)

I am not changing DC and I don't have those extra pulses and everything seems to be working fine.

 

UPDATE

I just came across slvc106 and now I know which chart and flag you are talking about.

[pillum 0]

Hmmm, can I use GND as Low?

 

VPRG can be either GND or VCC but DCPRG can be either L or H..is there any difference?

Because I really dont know whats not working again, all the signals and connections are checked and are all right

[pillum 0]

edit: seems like my 1.3 Pin is broken now.

simple main.c with only activating it, gives GND on it