AT88SC0204C-SU ATMEL [ATMEL Corporation], AT88SC0204C-SU Datasheet - Page 9

• Manufacturer Part Number: AT88SC0204C-SU
• Description: CryptoMemory 2 Kbit
• Manufacturer: ATMEL [ATMEL Corporation]

Security Fuses
Protocol Selection
Asynchronous
T = 0 Protocol
Synchronous
2-wire Serial Interface
2022HS–SMEM–04/07
There are three fuses on the device that must be blown during the device personaliza-
tion process. Each fuse locks certain portions of the configuration memory as OTP
memory. Fuses are designed for the module manufacturer, card manufacturer and card
issuer and should be blown in sequence, although all programming of the device and
blowing of the fuses may be performed at one final step.
The AT88SC0204C supports two different communication protocols.
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•
The power-up sequence determines which of the two communication protocols will be
used.
This power-up sequence complies with ISO 7816-3 for a cold reset in smart card
applications.
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•
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•
The device will respond with a 64-bit ATR code, including historical bytes to indicate the
memory density within the CryptoMemory family. Once the asynchronous mode has
been selected, it is not possible to switch to the synchronous mode without powering off
the device.
Figure 10. Asynchronous T = 0 Protocol (Gemplus Patent)
The synchronous mode is the default after powering up V
on RST. For embedded applications using CryptoMemory in standard plastic packages,
this is the only communication protocol.
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•
CLK-SCL
Smart Card Applications: The asynchronous T = 0 protocol defined by ISO 7816-3
is used for compatibility with the industry’s standard smart card readers.
Embedded Applications: A 2-wire serial interface is used for fast and efficient
communication with logic or controllers.
V
Set I/O-SDA in receive mode.
Provide a clock signal to CLK-SCL.
RST goes high after 400 clock cycles.
Power-up V
After stable V
I/O-SDA
CC
RST
goes high; RST, I/O-SDA and CLK-SCL are low.
V cc
CC
CC
, RST goes high also.
, CLK-SCL and I/O-SDA may be driven.
CC
AT88SC0204C
due to the internal pull-up
ATR
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