topic Re: Phantom ILDMAS, UART IDLE line DMA Enable in Kinetis Microcontrollers

Phantom ILDMAS, UART IDLE line DMA Enable

pmt — Wed, 24 Oct 2012 20:11:04 GMT

A number of the Kinetis Reference Manuals make reference to 'ILDMAS' in UART register C5. Presumably this would allow DMA generation on an IDLE line condition (instead of an interrupt). But no such bit is shown in the C5 register definition. Was the ILDMAS functionality disabled in Kinetis, or is there a mistake in the manual?

pmt

Re: Phantom ILDMAS, UART IDLE line DMA Enable

apanecatl — Thu, 07 Feb 2013 14:37:59 GMT

I'm afraid that is a documentation error, ILDMAS in UART are not supported in Kinetis microcontrollers.

Re: Phantom ILDMAS, UART IDLE line DMA Enable

michaelguntli — Wed, 18 Nov 2015 07:01:46 GMT

Is someone from Freescale able to share the motivation why the ILDMAS (Idle DMA request) has been removed?

The DMA UART Rx is basically useless without this feature, because the data length which is received from UART is not known in 99% of the use cases...

DISCUSSION: Missing critical RX UART DMA Event Functionality in Freescale Parts

FYI: Generating an interrupt on each byte receiption is not an accepted workaround, because this would make the whole DMA use case kind of useless..