A question about GPIO on MC13213

[VincentLau]

Hi,

   I am a newer on freescale 8-bit MCU. I know that all unused modem GPIOx should programmed as outputs in the low state when the MCU goes to Hibernate or Doze modes according to the document MC1321x.pdf on page 65. My question is that how can I operate on it, I have not seen any register about GPIO from any documents. I also check MC13213.h created automatically by Coderwarrior, but I have found nothing on it either.

  Can anyone help me? Thank you very much!

Best Regards

Vincent

Sep24,2008

[Andrey]

Basically when it refers to GPIO1-7 it  refers to a modem part

page 12 says
"The transceiver GPIO pins default to inputs at reset. There are no programmable pullups on these pins. Unused GPIO pins should be tied to ground if left as inputs, or if left unconnected, they should be programmed as outputs set to the low state. During low power modes, input must remain driven by MCU."

Take a look at MC1321xRM.pdf page 5-15 

gpio7_oen and so on.


Message Edited by Andrey on 2008-09-26 02:38 PM

[Andrey]

When it is talking about the GPIOx it means ANY general purpose input/output register (i.e. PTC7, PTC6...PTD3, PTE4)
For example, to set them as outputs in the low state use:

Code:

//PIN DIRECTION (1 == OUTPUT, 0 = INPUT)  PTADD_PTADD0 = 1; // CTRL1 // SHUTTER ELECTO-MAGNET//LEVEL ON THE PIN (FOR OUTPUTS ONLY)  PTAD_PTAD0 = 0; // LOW STATE

 Do that for all of the GPIOs that you don't use.

[VincentLau]

Hi, Andrey

   Thank you for your warmhearted reply! However, I see there are special GPIO1-4 on pin 44-41, and GPIO5-7 on pin 24-26 of MC13213 pinout. I don't know what they are.

Best Regards

Vincent

Set25,2008