LPC1857_53 NXP Semiconductors, LPC1857_53 Datasheet - Page 82

• Manufacturer Part Number: LPC1857_53
• Description: The LPC1857/53 are ARM Cortex-M3 based microcontrollers for embedded applications
• Manufacturer: NXP Semiconductors

NXP Semiconductors
LPC1857_53
Objective data sheet
CAUTION
7.21 Emulation and debugging
There are three levels of the Code Read Protection:
Debug and trace functions are integrated into the ARM Cortex-M3. Serial wire debug and
trace functions are supported in addition to a standard JTAG debug and parallel trace
functions. The ARM Cortex-M3 is configured to support up to eight breakpoints and four
watch points.
•
•
•
In level CRP1, access to the chip via the JTAG is disabled. Partial flash updates are
allowed (excluding flash sector 0) using a limited set of the ISP commands. This level
is useful when CRP is required and flash field updates are needed. CRP1 does
prevent the user code from erasing all sectors.
In level CRP2, access to the chip via the JTAG is disabled. Only a full flash erase and
update using a reduced set of the ISP commands is allowed.
In level CRP3, any access to the chip via the JTAG pins or the ISP is disabled. This
mode also disables the ISP override using P2_7 pin. If necessary, the application
code must provide a flash update mechanism using the IAP calls or using the
reinvoke ISP command to enable flash update via USART0.
If level three Code Read Protection (CRP3) is selected, no future factory testing can be
performed on the device.
All information provided in this document is subject to legal disclaimers.
Rev. 1 — 14 December 2011
32-bit ARM Cortex-M3 microcontroller
LPC1857/53
© NXP B.V. 2011. All rights reserved.
82 of 131