at88sc0104c ATMEL Corporation, at88sc0104c Datasheet - Page 40

• Manufacturer Part Number: at88sc0104c
• Description: Cryptomemory Specification For Standard Mode Of Operation
• Manufacturer: ATMEL Corporation

8.3.1
8.3.2
8.3.3
8.3.4
36
AT88SC0104/0204/0404/0808/1616/3216/6416/12816/25616C
Example 1
Example 2
Example 3
Example 4
After the ATR, the reader will have the choice of proceeding with commands using default val-
ues of F=372 and D=1 (9600 baud at 3.5712 MHz), or negotiating values Fn and Dn through a
PPS exchange. Following are four examples of PPS requests and responses:
We assume the CryptoMemory ATR contains the byte TA(1) = 15h, indicating that it is capable
of using F=372 and D=16, leading to a baud rate of 153,600 baud at 3.5712 MHz. Assuming that
this is the maximum speed supported by the device, the reader immediately attempts to set the
F and D parameters leading to these values.
The newly negotiated values are effective immediately following this exchange, so that the ETU,
or duration of one bit on I/O, will now be 23 clock cycles instead of 372.
The reader insists on negotiating Fn and Dn equal to the default values, even though these
would be used by default without the use of a PPS exchange. The two ways of doing this are by
sending PPS1_request = $11 or not sending PPS1_request at all.
The reader attempts to negotiate values that are not supported by the CryptoMemory device. In
its response, the CryptoMemory proposes to continue with F and D, by not sending
PPS1_response. Even though new Fn and Dn values aren’t negotiated, this scenario is still con-
sidered a “successful” exchange according to ISO 7816.
If the reader attempts to change the protocol to any protocol other than T = 0, such as T = 1, the
CryptoMemory will indicate that it only supports T = 0.
• PPS_request =$FF $10 $15 $FA
• PPS_response = $FF $10 $15 $FA
• PPS_request = $FF $10 $11 $FE
• PPS_response= $FF $10 $11 $FE
• PPS_request= $FF $00 $FF
• PPS_response = $FF $00 $FF
• PPS_request= $FF $10 $45 $AA
• PPS_response= $FF $00 $FF
• PPS_request= $FF $01 $FE
• PPS_response= $FF $00 $FF
or
5210A–SMIC–04/07