Datasheet

DS_8024RN_020 73S8024RN Data Sheet
Rev. 2 7
2 System Controller Interface
Three separated digital inputs allow direct control of the card interface from the host as follows:
• Pin CMDVCC: When low, starts an activation sequence.
• Pin RSTIN: controls the card Reset signal (when enabled by the sequencer).
• Pin 5V/#V: Defines the card voltage.
Card clock is controlled by four digital inputs:
• CLKDIV1 and CLKDIV2 define the division rate for the clock frequency, from the input clock
frequency (crystal or external clock).
• CLKSTOP (active high) allows card power down mode by stopping the card clock.
• CLKLEV defines the card clock level of the card power down mode.
Interrupt output to the host: As long as the card is not activated, the OFF pin informs the host about the
card presence only (Low = No card in the reader). When CMDVCC is set low (Card activation sequence
requested from the host), low level on OFF means a fault has been detected (e.g. card removal during
card session, or voltage fault, or thermal / over-current fault) that automatically initiates a deactivation
sequence.