ACR89U-A1 – Reference Manual
Version 1.04
www.acs.com.hk
Page 6 of 57
bytes)
Bulk IN
– For commands to be sent from ACR89U-A1 to host (data packet size is 64
bytes)
Interrupt IN
– For card status message to be sent from ACR89U-A1 to host (data packet size
is 8 bytes)
2.5. Contact Smart Card Interface
The interface between the ACR89U-A1 and the inserted smart card follows the specifications of ISO
7816-3 with certain restrictions or enhancements to increase the practical functionality of the
ACR89U-A1.
2.5.1.
Smart Card Power Supply VCC (C1)
The current consumption of the inserted card must not be higher than 50 mA.
2.5.2.
Card Type Selection
Before activating the inserted card, the controlling PC always needs to select the card type through
the proper command sent to the ACR89U-A1.
For MCU-based cards the reader allows to select the preferred protocol, T=0 or T=1. However, this
selection is only accepted and carried out by the reader through the PPS when the card inserted in
the reader supports both protocol types. Whenever an MCU-based card supports only one protocol
type, T=0 or T=1, the reader automatically uses that protocol type, regardless of the protocol type
selected by the application.
2.5.3.
Interface for Microcontroller-based Cards
For microcontroller-based smart cards only the contacts C1 (VCC), C2 (RST), C3 (CLK), C5 (GND)
and C7 (I/O) are used. A frequency of 4.8 MHz is applied to the CLK signal (C3).
