MSP430I2040: DCO frequency 4MHz too low

Alessio Bollazzi

Part Number: MSP430I2040
Other Parts Discussed in Thread: EVM430-I2040SUBMTR, EVM430-I2040S

I'm using a MSP430I2040 on a custom PCB and on a EVM430-I2040SUBMTR demo board and when I measure the clock frequency on a GPIO Pin I get 12MHZ MCLK and 24.05kHz ACLK on both MSPs. It should be 16MHz and 31.25kHz. I'm not using any prescaler, so I don't know why I'm getting such low frequencies.

Alessio

over 6 years ago

0 James Evans over 6 years ago

TI__Mastermind 49692 points

Hello Alessio,

Welcome to E2E! Assuming MCLKDIV is set to 1, you should be measuring 16.384MHz for MCLK on P1.0. Are you using an oscilloscope to measure this frequency or something else? Have these devices been damaged by ESD, over-voltage, etc.? What code are you using? I'd recommend that you try one of our code examples.

If you're using the EVM430-i2040S, then keep in mind that other components on these pins like LED7 are most likely affecting the frequency measurements due to capacitance, etc.

By the way, do you plan on using the Energy Measurement Design Center (EMDC) for your project? It definitely makes the software development easier.

Accelerate your metering design with the new Energy Measurement Design Center and software library for MSP430™ MCUs

Regards,

James

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MSP430I2040: DCO frequency 4MHz too low