ACR101I – Reference Manual
Version 1.01
www.acs.com.hk
Page 9 of 21
7.0. Communication Protocol
ACR101 (CCID) interfaces with the host via USB connection. It is a compounded device consisting of
two interfaces: Chip Card Interface Device and Mass Storage.
The ACR101 (CCID) Smart Card Interface shares the same core as the smart card interface of the
ACR38 CCID. The Smart Card Interface will be identified as “ACR38-112c” once the reader FW is
obtained. CCID covers all the protocols required for operating smart cards and PIN.
Note: The command for this will be discussed later on.
The configurations and usage of USB endpoints on ACR101 (CCID) Smart Card Interface shall follow
CCID Section 3. An overview is summarized below:
1.
Control Commands
are sent on control pipe (default pipe). These include class-specific
requests and USB standard requests. Commands that are sent on the default pipe report
information back to the host on the default pipe.
2.
CCID Events
are sent on the interrupt pipe.
3.
CCID Commands
are sent on
Bulk-OUT
endpoint. Each command sent to smart card reader
has an associated ending response. Some commands can also have intermediate responses.
4.
CCID Responses
are sent on
Bulk-IN
endpoint. All commands sent to the smart card reader
have to be sent synchronously. (i.e.,
bMaxCCIDBusySlots
is equal to 1)
The supported CCID features by ACR101 (CCID) smart card interface are indicated in its Class
Descriptor:
Offset
Field
Size
Value
Description
0
bLength
1
36h
Size of this descriptor, in bytes.
1
bDescriptorType
1
21h
CCID Functional Descriptor type.
2
bcdCCID
2
0100h
CCID Specification Release Number in
binary-coded decimal.
4
bMaxSlotIndex
1
00h
One slot is available
5
bVoltageSupport
1
07h
The smart card reader can supply 1.8 V,
3.0 V and 5.0 V to its slot.
6
dwProtocols
4
00000003h
The smart card reader supports T=0 and
T=1 Protocol
10
dwDefaultClock
4
00000FA0h
Default ICC clock frequency is 4 MHz
14
dwMaximumClock
4
00000FA0h
Maximum supported ICC clock frequency
is 4 MHz
18
bNumClockSupported
1
00h
Does not support manual setting of clock
frequency
19
dwDataRate
4
00002A00h
Default ICC I/O data rate is 10752 bps
23
dwMaxDataRate
4
0001F808h
Maximum supported ICC I/O data rate is
344 Kbps
27
bNumDataRatesSupported
1
00h
Does not support manual setting of data
rates
28
dwMaxIFSD
4
00000Feh
Maximum IFSD supported by the smart
card reader for protocol T=1 is 254
