[Muscle] IFD_POWER_UP and IFD_POWER_DOWN actions in IFDHPowerICC() function?

[Peter Tomlinson]

Geoff Elgey wrote:

>  G'day,
>
>  I've written a IFD handler for a memory card, but I am now wondering
>  if I am handling the IFDHPowerICC() function correctly.
>
>  The function documentation defines the 'action' parameter as follows:
>
>
>  * IFD_POWER_UP
>
>  Power and reset the card if not done so
>
>  * IFD_POWER_DOWN
>
>  Power down the card then power up if not done already
>
>  So what is the difference between "power up and reset" (the
>  IFD_POWER_UP action) and "power down and power up" (the
>  IFD_POWER_DOWN action)?
>
>  The IFD_POWER_DOWN case does not mention card reset after power up.
>  What does it mean (in terms of card state) to have a card that is
>  powered up but not reset?
>
For compliance with ISO/IEC 7816, the card reader must follow the 
correct sequence when powering up the card, i.e. must ensure that the 
card is held in the Reset state until power (and, for a microprocessor 
card, clock) is established as specified in the standard. If, however, 
your card is not 7816 compliant (e.g. if it is an I2C card), you are 
outside the coverage of 7816.

Peter