MCB2103: DEVICE MAY FAIL AT HIGH CLOCK SPEEDS

Information in this article applies to:

• MCB2103 Evaluation Boards

SYMPTOM

The MCB2103 has problems running code at 70 MHz, and also at 40-60MHz if the peripherals are running at the same speed or at half the speed of the core.

CAUSE

There is a known problem with the first revision of the LPC2103 devices. The device may not work properly under increased power consumption conditions. The likelihood of the problem showing up increases if the device is run at higher speeds (approaching 70MHz) and/or if the peripherals are running at close to the same speed as the core (i.e. When the APBDIV register is set to a value lower than 4, which implies that the peripherals run faster than 1/4 of the system frequency).

RESOLUTION

There are 2 ways to resolve this:

• Run the LPC2103 core and/or peripherals at lower speed by making sure that the APB divider register is set to 0. This ensures that the peripherals run slower than the CPU core.
• Increase the voltage on Vdd1V8 by replacing the 1.8V regulator with a 2.0V regulator.

MORE INFORMATION

• MCB2103 Schematic Diagram

SEE ALSO

• MCB2103: PORT LEDS DO NOT DISPLAY AS EXPECTED

Last Reviewed: Monday, September 11, 2006