ACS ACR38K Smart Keyboard - Manual (Page 9)

ACR38x (CCID) – Reference Manual [email protected]
Version 6.04 www.acs.com.hk
Page 9 of 58
6.0. USB Interface
6.1. Communication Parameters
The ACR38x (CCID) is connected to a computer through USB as specified in the USB Specification
2.0. The ACR38x (CCID) is working in full speed mode, i.e. 12 Mbps.
Pin Signal Function
1 V
BUS
+5 V power supply for the reader
2 D- Differential signal transmits data between ACR38x (CCID) and PC
3 D+ Differential signal transmits data between ACR38x (CCID) and PC
4 GND Reference voltage level for power supply
Table 2: USB Interface Wiring
Note: In order for the ACR38x (CCID) to function properly through USB interface, either ACS CCID
driver or the Microsoft CCID driver has to be installed.
6.2. Endpoints
The ACR38x (CCID) uses the following endpoints to communicate with the host computer:
Control Endpoint For setup and control purpose
Bulk OUT
For command to be sent from host to ACR38x (CCID)
(data packet size is 64 bytes)
Bulk IN
For response to be sent from ACR38x (CCID) to host
(data packet size is 64 bytes)
Interrupt IN
For card status message to sent from ACR38x (CCID) to
host
(data packet size is 8 bytes)