MCB1800: LPC1857: Could not stop Cortex-M device

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Information in this knowledgebase article applies to:

• Keil MCB1857 Evaluation Board with LPC1857
• Keil MDK 5

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SYMPTOM

Keil populates the MCB1857 Evaluation Board with an NXP LPC1857 device.

Building an example project provided by the Pack Installer succeeds.

But then I see an error, i.e. at a LOAD command like:

 Could not stop Cortex-M device! Please check the JTAG cable.

CAUSE

Such a problem may arise because of, i.e.:

1. wrong Jumper settings (if no valid image exists on the device)

2. a different microcontroller populated on your board

3. Debug Description enabled

RESOLUTION

1. Set the boot configuration jumpers to the default settings (EMC 32):

       P2_9, P2_8, P1_2, P1_1

       L H L L: EMC 32-bit

2. There are some MCB1850 boards sold, where the microcontroller does not have on-chip flash.

    The label on the microcontroller should show LPC1857 and NOT LPC1850.

3. Disable the Debug Description defined at the Keil::LPC1800_DFP:

MORE INFORMATION

• Refer to MCB1800

• Refer to Configuring the MCB1800 in the MCB1800/4300 User's Guide.

• Refer to Jumper Descriptions in the MCB1800/4300 User's Guide.

SEE ALSO

• Refer to ULINK: Could Not Stop Cortex-M Device

Last Reviewed: Thursday, October 22, 2020

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