Chapter 8 Security - NXP Semiconductors freescale KV4 Series Reference Manual

Chapter 8
Security
8.1 Introduction
This device implements security based on the mode selected from the flash module. The
following sections provide an overview of flash security and details the effects of security
on non-flash modules.
8.2 Flash Security
The flash module provides security information to the MCU based on the state held by
the FSEC[SEC] bits. The MCU, in turn, confirms the security request and limits access to
flash resources. During reset, the flash module initializes the FSEC register using data
read from the security byte of the flash configuration field.
The security features apply only to external accesses via debug.
CPU accesses to the flash are not affected by the status of
FSEC.
In the unsecured state all flash commands are available to the programming interfaces
(JTAG), as well as user code execution of Flash Controller commands. When the flash is
secured (FSEC[SEC] = 00, 01, or 11), programmer interfaces are only allowed to launch
mass erase operations and have no access to memory locations.
Further information regarding the flash security options and enabling/disabling flash
security is available in the
Freescale Semiconductor, Inc.
NOTE
Flash Memory Module.
KV4x Reference Manual, Rev. 2, 02/2015
Preliminary
115