MCF548x Reference Manual, Rev. 3
Freescale Semiconductor 22-1

Chapter 22

Integrated Security Engine (SEC)

This chapter provides an overview of the MCF548x security encryption controller (SEC).
NOTE
Purchasing any of the MCF548x devices with security requires government
export control regulation.

22.1 Features

The SEC is designed to offload computationally intensive security functions, such as authentication bulk
encryption from the MCF548x core. It is optimized to process all the algorithms associated with IPSec,
SSL/TLS, iSCSI, and SRTP.
SEC features include the following:
DEU—data encryption standard execution unit
DES, 3DES
Two key (K1, K2, K1) or three Key (K1, K2, K3)
ECB and CBC modes for both DES and 3DES
AESU—advanced encryption standard unit
Implements the Rinjdael symmetric key cipher
ECB, CBC, CCM, and counter modes
128, 192, 256 bit key lengths
AFEU—ARC four execution unit
Implements a stream cipher compatible with the RC4 algorithm
40- to 128-bit programmable key
MDEU—message digest execution unit
SHA with 160-bit or 256-bit message digest
MD5 with 128-bit message digest
HMAC with either algorithm
RNG—one random number generator
Master/slave logic, with DMA
32-bit address/32 -bit data
Up to 133 MHz operation
Two Crypto-channels, each supporting multi-command descriptor chains
Static and/or dynamic assignment of crypto-execution units via an integrated controller
Buffer size of 512 bytes for each execution unit, with flow control for large data sizes

22.2 ColdFire Security Architecture

The ability of the SEC to be a master on the internal XLB bus allows the security core to offload the data
movement bottleneck normally associated with slave-only cores.
The ColdFire core accesses the SEC primarily through data packet descriptors using system memory for
data storage. When an application requires cryptographic functions, it simply creates descriptors that