UM10413
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© NXP B.V. 2011. All rights reserved.
User manual
Rev. 1 — 16 December 2011
217 of 268
NXP Semiconductors
UM10413
MPT612 User manual
25. Flash memory system and programming
25.1 Introduction
The MPT612 has three levels of Code Read Protection (CRP) implemented:
•
CRP1: disables access to chip via the JTAG pins and allows partial flash updates
(excluding flash sector 0) using a limited set of the ISP commands. This mode is
useful when CRP is required and flash field updates are needed but all sectors cannot
be erased
•
CRP2: disables access to chip via the JTAG pins and only allows full flash erase and
update using a reduced set of the ISP commands
•
CRP3: running an application with this level, fully disables any access to chip via the
JTAG pins and ISP. This mode effectively disables ISP override using pin PIO14. The
user’s application must provide a flash update mechanism (if needed) using IAP calls,
or call the re-invoke ISP command to enable flash update via pin UART0.
25.2 Boot
loader
The bootloader controls initial operation after reset and also provides the means to
accomplish programming of the flash memory. This could be initial programming of a
blank device, erasure and reprogramming of a previously programmed device, or
programming of the flash memory by the application program in a running system.
25.3 Features
•
In-System Programming: In-System Programming (ISP) is the programming or
reprogramming of the on-chip flash memory using the bootloader software and a
serial port. This can be done when the part resides in the end-user board.
•
In-Application Programming: In-Application (IAP) Programming performs erase and
write operations on the on-chip flash memory, as directed by the end-user application
code.
25.4 Applications
The bootloader provides both In-System and In-Application Programming interfaces for
programming the on-chip flash memory.
25.5 Description
The bootloader code is executed every time the part is powered on or reset. The loader
can execute the ISP command handler or the user application code. A LOW level after
reset at pin PIO14 is considered as an external hardware request to start the ISP
Table 210. Recommended values for the RTC external 32 kHz oscillator C
X1/X2
components
Crystal load capacitance
C
L
Maximum crystal series
resistance R
S
External load capacitors C
X1
,
CX2
11 pF
< 100 k
18 pF, 18 pF
13 pF
< 100 k
22 pF, 22 pF
15 pF
< 100 k
27 pF, 27 pF