ATPL230A datasheet(25/122 Pages) ATMEL

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ATPL230A [DATASHEET]

Atmel-43053J-ATPL230A-Datasheet_22-Sep-16

8.1.2

Configurable CRC calculation

PRIME v1.3 version fixes the polynomial to calculate the CRCs. In case that these polynomials were modified, the

CRC peripheral would be used. It is used as a peripheral unit, accessible using the system peripheral registers.

For example, to configure it for PRIME CRC8:

X^8 + X^2 + X + 1

VCRC_POLY = 0x00000007

VCRC_RST = 0x00000000

VCRC_CONF = 0xC0

And to configure it for PRIME CRC32:

x^32 + x^26 + x^23 + x^22 + x^16 + x^12 + x^11 + x^10 + x^8 + x^7 + x^5 + x^4 + x^2 + x + 1

VCRC_POLY = 0x04C11DB7

VCRC_RST = 0x00000000

VCRC_CONF = 0xC3

A different set of registers can also be used to set CRC parameters:

X^12 + X^11 + X^3 + X^2 + X + 1

PRIMEPLUS_CRC_POLY = 0x080F

PRIMEPLUS_CRC_RST = 0x0000

PRIMEPLUS_CRC_CONFIG = 0x14

8.2

Advanced Encryption Standard (AES)

One of the additional security functionalities to PRIME v1.3 is the 128-bit AES encryption of data. ATPL230A includes

a hardware implementation of this block, as a peripheral unit.

In transmission, data must be encrypted previously to the use of the PHY_DATA request primitive (see PRIME

specification), in an independent way (note that Beacon PDU, Promotion PDU and Generic MAC header, as well as

several control packets, are not encrypted).

In reception, data passed by the PHY layer is already encrypted and must be decrypted in a subsequent process.

To encrypt a data package with corresponding KEY, the process is as follows:

1. Write the KEY (128 bits long) in AES_KEY register. This step is only needed if a new key is going to be

used (due to a key change or to a reset operation).

2. Write the 128 bits of data to be encrypted in AES_DATA register.

3. Set to ‘1’ the CIPHER control bit in AES_CTL register and then set to ‘1’ the START control bit to start the

operation. This step could be realized as an atomic operation writing 0x03.

4. Wait until the READY bit in AES_CTL register becomes ‘1’ automatically. This bit indicates when the

operation is completed.

5. After that, the encrypted (coded) data package is automatically stored in AES_DATA register.

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