Margin Read Commands - NXP Semiconductors freescale KV4 Series Reference Manual

FCMD
0x02
0x03
0x06
0x09
0x40
0x41
0x43
0x44
0x45

32.4.9 Margin Read Commands

The Read-1s commands (Read 1s All Blocks and Read 1s Section) and the Program
Check command have a margin choice parameter that allows the user to apply non-
standard read reference levels to the program flash array reads performed by these
commands. Using the preset 'user' and 'factory' margin levels, these commands perform
their associated read operations at tighter tolerances than a 'normal' read. These non-
standard read levels are applied only during the command execution. All simple
(uncommanded) flash array reads to the MCU always use the standard, un-margined, read
reference level.
Only the 'normal' read level should be employed during normal flash usage. The non-
standard, 'user' and 'factory' margin levels should be employed only in special cases.
They can be used during special diagnostic routines to gain confidence that the device is
not suffering from the end-of-life data loss customary of flash memory devices.
Freescale Semiconductor, Inc.
Command
Program Check
Read Resource
Program Longword
Erase Flash Sector
Read 1s All Blocks
Read Once
Program Once
Erase All Blocks
Verify Backdoor Access Key
KV4x Reference Manual, Rev. 2, 02/2015
Preliminary
Chapter 32 Flash Memory Module (FTFA)
Program flash
×
IFR, ID
×
×
×
IFR
IFR
×
×
Function
Tests previously-programmed
locations at margin read
levels.
Read 4 bytes from program
flash IFR or version ID.
Program 4 bytes in a program
flash block.
Erase all bytes in a program
flash sector.
Verify that the program flash
block is erased then release
MCU security.
Read 4 bytes of a dedicated
64 byte field in the program
flash 0 IFR.
One-time program of 4 bytes
of a dedicated 64-byte field in
the program flash 0 IFR.
Erase the program flash
block, verify-erase and
release MCU security.
NOTE: An erase is only
possible when all
memory locations
are unprotected.
Release MCU security after
comparing a set of user-
supplied security keys to
those stored in the program
flash.
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