topic Re: JN5169 MAC PIB Attributes (Missing) in Wireless MCU

JN5169 MAC PIB Attributes (Missing)

mferrari1 — Thu, 06 Jun 2019 18:14:35 GMT

The MAC PIB Attributes are documented in the NXP IEEE802.15.4 Stack User Guide (JN-UG-3024) Chapter 8.

Some of the Attributes are not mentioned in this document.

Of particular interest to me are: u8MaxFrameRetries & u16MaxTotalFrameTxTime

Why do these attributes not appear in the User Guide MAC PIB documentation?

Can anyone point me to NXP documentation which discusses the usage of these attributes as they are implemented in the NXP 802.15.4 Stack?

Thanks, Matt

Re: JN5169 MAC PIB Attributes (Missing)

stephanie_m — Fri, 07 Jun 2019 16:03:12 GMT

Hello,

I looked in my available files and was not able to locate anything as well, I'll check if we have the information available to share.

Regards,

Estephania

Re: JN5169 MAC PIB Attributes (Missing)

MattGillespie — Wed, 19 Jun 2019 10:46:50 GMT

The document is not up to date as these attributes were added later, but I do have the following information:

u8MaxFrameRetries is the number of retry attempts if a frame transmission is not acknowledged. So if u8MaxFrameRetries = 2, the frame will be retransmitted up to 2 times (hence 3 transmits in total).

u16MaxTotalFrameTxTime is the time that the device will stay in RX waiting for a frame when it expects one, e.g. after a data request where the acknowledge has indicated that a frame is pending. The value should be determined from the values of minBE, maxBE and maxCSMAbackoffs using a slightly complicated formula that is in the 802.15.4 spec (for 802.15.4-2011 it is in section 6.4.3, but in any version just search for macMaxFrameTotalWaitTime).

The default value is correct for the defaults of the other values.

Note: There are 2 MAC stacks released in the JN5169 SDK. The full MAC is a complete implementation of all the functionality in the 15.4 specification. We also release the MiniMac that is used in the Zigbee applications as it is a much smaller implementation and only includes the functionality required by Zigbee and has a smaller footprint of both flash and RAM. In the MiniMac implementation, this PIB variable changed name to u16MaxFrameTotalWaitTime to better match the name used by the 15.4 specification.

Re: JN5169 MAC PIB Attributes (Missing)

mferrari1 — Wed, 19 Jun 2019 18:16:13 GMT

Thank you Matt!