Explanation of KL43Z features (ROM bootloader and USB crystal-less operation)

[piotrcerba]

Hello, while reading about KL43Z I stumbled across this article Unboxing the Freescale FRDM-KL43Z Board | MCU on Eclipse by Erich Styger.

I wanted to ask what are the benefits/drawbacks of this separate ROM bootloader and crystal-less USB operation in comparison with eg. KL46Z.

Why are LDD not supported? What limitations does it put?

[Hui_Ma · Accepted solution]

Hi,

The ROM Bootloader will provides USB/I2C/SPI/LPUART bootloader without related code development processing and customer can use full Flash range for application (if customer using bootloader software, which need to occupied some range of Flash memory).

The crystal-less USB module brings obviously benefit for customer to reduce the BOM cost.

The KSDK V1.2.0 supports FRDM-KL43Z board with related HAL/Peripheral driver.

I don't think Processor Expert LDD component missing could affect FRDM-KL43Z board application.

More detailed info about KSDK for KL43Z could be found here.

Wish it helps.

Have a great day,
Ma Hui

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[mjbcswitzerland]

Hi

Crystal-less operation:

1. Saves costs because no crystal or oscillator is required

2. Restrictions:

- USB host is not possible (device is)

- Since the IRC48M is not synchronised when USB is not connected, the processor's time base (for timing, generating clocks, Baud rates) will not be as accurate (also have more temperature drift) as when there is an accurate reference available.

See also:

µTasker MCG Configuration Support

Notes to uTasker project usage:

To use IRC48M for USB device source just enable the project define USB_CRYSTAL_LESS

To clock the processor directly from the IRC48M source set RUN_FROM_HIRC

Regards

Mark

Kinetis: µTasker Kinetis support

KL43: µTasker FRDM-KL43Z support  / µTasker TWR-KL43Z48M support

For the complete "out-of-the-box" Kinetis experience and faster time to market