Hi,
Basically i am doing some Smart card application. I need to interface with smart card.
although MAXIM and other IC company provides level-shifter for smart card interface IC, but i try to see if i can avoid to use them.
as far as i know, level-shifter ic is shift the voltage plus output some defined bit for certain operation. I guess i can produce the defined bit by using uC. I am not sure if I can change the ouput voltage level of uC.
Smart card needs 2 input voltage (VCC and VPP), and 1 IO pin.
The thing is smart card may run at 3 kind of voltage, 5v, 3v and 1.8v.
and also the smart card may run at different clock speed.
The way to determine the voltage and clock speed required is 1st sendind and ATR request, using a predefined initial frequency, and the card will return all the operating condition.
So I will need to change the voltage level and frequency aft the 1st ATR.