• TI Thinks Resolved

DLPD4X00KIT: Question for SetPWRFLOAT function

Prodigy 60 points

Replies: 2

Views: 84

Part Number: DLPD4X00KIT

I have two questions for SetPWRFLOAT function in USB DLL API.
Do anyone know this issue?

  • Question 1. Is it different from DMD Park Request?

I thought that executing SetPWRFLOAT function is equal to issuing "DMD Park Request",
but I realized the DMD does not stay in park state unless both of them are executed.
Like this. Is it correct procedure?

			// DMD Block Operations -- DMD Park Request
			SetBlkMd(3, deviceNumber); // BLK_MD=2'b00
			SetBlkAd(12, deviceNumber); // BLK_AD=4'b11xx
			LoadControl(deviceNumber);

			SetPWRFLOAT(0, deviceNumber);

  • Question 2. Is its 1st argument's polarity correct?

In DLPU039a at 6.2.20 section, it describes "Active=1, inactive=0".
But, as far as I tried my own C++ code, the DMD shows park state behaviour when SetPWRFLOAT(0, ..).
What I say "park state behaviour" means the same behaviour as pushing DLPDiscovery4100 board's SW3.
And I'm checking the DMD by watching its surface directly with my eyes.

  • Hello again Goro,

    Yes they are different.  The first method (i.e. Park request) is recoverable by sending  a reset operation which will resume normal operation.  PWRFLOAT (either the command or the switch (SW3) prepares for shutdown and is not recoverable without doing a full logic Reset (i.e. powering down or pulling the RESET_Z of the controller).

    Fizix

  • In reply to Fizix:

    Hi Fizix, thank you for your reply.
    I understand that SetPWRFLOAT function and SW3 are the same behavior.

    Can I ask another question here?
    Before power down the DLPDiscovery4100 board, Does SetPWRFLOAT function have to be executed? Or, is only issuing "Park request" enough?