LPC2361_62 NXP Semiconductors, LPC2361_62 Datasheet - Page 31

• Manufacturer Part Number: LPC2361_62
• Description: The LPC2361/2362 microcontrollers are based on a 16-bit/32-bit ARM7TDMI-S CPU with real-time emulation that combines the microcontroller with up to 128 kB of embedded high-speed flash memory
• Manufacturer: NXP Semiconductors

NXP Semiconductors
LPC2361_62
Product data sheet
CAUTION
7.24.2 Brownout detection
7.24.3 Code security (Code Read Protection - CRP)
7.24.4 AHB
The LPC2361/2362 includes 2-stage monitoring of the voltage on the V
If this voltage falls below 2.95 V, the BOD asserts an interrupt signal to the Vectored
Interrupt Controller. This signal can be enabled for interrupt in the Interrupt Enable
Register in the VIC in order to cause a CPU interrupt; if not, software can monitor the
signal by reading a dedicated status register.
The second stage of low-voltage detection asserts Reset to inactivate the LPC2361/2362
when the voltage on the V
alteration of the flash as operation of the various elements of the chip would otherwise
become unreliable due to low voltage. The BOD circuit maintains this reset down below
1 V, at which point the power-on reset circuitry maintains the overall Reset.
Both the 2.95 V and 2.65 V thresholds include some hysteresis. In normal operation, this
hysteresis allows the 2.95 V detection to reliably interrupt, or a regularly executed event
loop to sense the condition.
This feature of the LPC2361/2362 allows user to enable different levels of security in the
system so that access to the on-chip flash and use of the JTAG and ISP can be restricted.
When needed, CRP is invoked by programming a specific pattern into a dedicated flash
location. IAP commands are not affected by the CRP.
There are three levels of the Code Read Protection.
CRP1 disables access to chip via the JTAG and allows partial flash update (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 can not be erased.
CRP2 disables access to chip via the JTAG and only allows full flash erase and update
using a reduced set of the ISP commands.
Running an application with level CRP3 selected fully disables any access to chip via the
JTAG pins and the ISP. This mode effectively disables ISP override using P2[10] pin, too.
It is up to the user’s application to provide (if needed) flash update mechanism using IAP
calls or call reinvoke ISP command to enable flash update via UART0.
The LPC2362 implements two AHBs in order to allow the Ethernet block to operate
without interference caused by other system activity. The primary AHB, referred to as
AHB1, includes the Vectored Interrupt Controller, GPDMA controller, USB interface, and
8 kB SRAM primarily intended for use by the USB.
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. 5 — 25 October 2011
DD(DCDC)(3V3)
pins falls below 2.65 V. This Reset prevents
Single-chip 16-bit/32-bit MCU
LPC2361/62
DD(DCDC)(3V3)
© NXP B.V. 2011. All rights reserved.
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pins.