AT88SC0104CA_11 ATMEL [ATMEL Corporation], AT88SC0104CA_11 Datasheet - Page 7

• Manufacturer Part Number: AT88SC0104CA_11
• Description: Atmel CryptoMemory Specification Datasheet
• Manufacturer: ATMEL [ATMEL Corporation]

4.
4.1
4.2
4.3
4.4
Pin Description
Supply Voltage (V
The V
Clock (SCL/CLK)
In the asynchronous T=0 protocol, the SCL/CLK input is used to provide the device with a carrier frequency f. The nominal
length of one bit emitted on I/O is defined as an "elementary time unit" (etu) and is equal to 372/ f. When the synchronous
protocol is used, the SCL/CLK input is used to clock data in on the positive clock edge and clock data out on the negative
clock edge.
Serial Data (SDA/IO)
The SDA pin is bi-directional for serial data transfer. This pin is open-drain driven and may be wired with any number of other
open drain or open collector devices. An external pull up resistor should be connected between SDA and V
of 4.7K ohm may be used. The value of this resistor and the system capacitance loading the SDA bus will determine the rise
time of SDA. This rise time will determine the maximum frequency during read operations. Low value pull up resistors will
allow higher frequency operations while drawing higher average power supply current.
Reset (RST)
CryptoMemory provides an ISO 7816-3 compliant asynchronous Answer-To-Reset (ATR) sequence. When the reset
sequence is activated, the device will output the data programmed into the 64-bit ATR register. When RST is low, all internal
logic, access rights and write cycles are in reset, except the asynchronous mode activation flag. A weak internal pull-up on the
RST input pad allows the device to be used in synchronous mode without bonding RST. For synchronous only smart card
applications an external pull-up on RST is recommended to ensure synchronous operation under any system timings or
conditions. CryptoMemory does not support a synchronous answer to reset sequence. The RST input is not available in the
plastic package options for CryptoMemory.
Figure 4-1. Connection Diagram
Note:
Microprocessor
CC
input is a 2.7V to 3.6V positive voltage supplied by the host.
While the Atmel CryptoMemory AT88SCXXXXCA is a low voltage device (2.7V to 3.6V) its I/O buffers are
designed for standard high voltage applications (2.7V to 5.5V)
CC
2.7v - 5.5v
)
Atmel AT88SC0104CA/0204CA/0404CA/0808CA [Datasheet]
SDA
SCL
CryptoMemory
2.7v - 3.6v
8664E−CRYPTO−12/11
CC
, a nominal value
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