ATSHA204A データシートの表示（PDF） - Atmel Corporation
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ATSHA204A Datasheet PDF : 82 Pages
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2. Device Organization
The device contains the following memory blocks:
EEPROM
SRAM
2.1 EEPROM Organization
The EEPROM contains a total of 664-bytes (5312-bits), and is divided into the following zones:
Data
A 512-byte (4Kb) zone split into 16 general-purpose, read-only, or read/write memory slots of 32 bytes
(256 bits) each that can be used to store keys, calibration data, model number, or other information
related to the item to which the ATSHA204A device is attached. Each slot may have different access
restrictions based on the values stored in the Configuration zone. Within this document the nomenclature
slot[yy] indicates the 32-byte value stored in slot yy of the Data zone.
Configuration
An 88-byte (704-bit) zone that contains serial number and other ID information as well as access
permission information for each slot of the data memory. Within this document the nomenclature SN[a:b]
indicates a range of bytes within a field of the configuration section. The 88-bytes are accessible from
within a three-block address space.
OTP (One Time Programmable)
A 64-byte (512-bit) zone which can be used to store read-only data or one-way (fuse type) consumption
logging information. Prior to locking the OTP zone, the bits may be freely written using the standard Write
command. The OTP zone is accessible from within a two-block address space. Within this document the
nomenclature OTP[bb] indicates a byte within the OTP zone, while OTP[aa:bb] indicates a range of bytes.
Within this document, the terms “slot” and “block” are used interchangeably to mean a single, 256-bit (32-byte)
area of a particular memory zone. Industry SHA-256 documentation uses the term “block” to indicate a 512-bit
section of the message input. In addition, the I/O section of this document uses the term “block” to indicate a
variable-length aggregate element transferred between the system and the device.
In this specification, the nomenclature mode:b indicates bit b of the parameter mode.
On shipment from Atmel, the EEPROM contains factory test data that can be used for fixed-value board testing.
This data must be overwritten with the desired contents prior to locking the configuration and/or data sections of
the device. See the Atmel website for the document containing the specific shipment values.
2.1.1
Data Zone
The Data zone is 512-bytes (4Kb), is part of the EEPROM array, and can be used for secure storage purposes.
Prior to locking the configuration section by using lock(Config), the Data zone is inaccessible and can be neither
read nor written. After configuration locking, the entire Data zone can be written using the Write command. If
desired, the data to be written can be encrypted.
In Table 2-1, “Byte Address” is the byte address within the Data zone for the first byte in the respective slot.
Because all Reads and Writes with the ATSHA204A are performed on a word (4-byte or 32-byte) basis, and the
word address in the table below should be used for the address parameter passed to the Read and Write
commands.
ATSHA204A [DATASHEET]
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Atmel-8885H-CryptoAuth-ATSHA204A-Datasheet_112015
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