Memory access arbitration in LPC55S69?

[tedhavelka1]

Hello NXP Community,

My name is Ted, and I'm developing a Zephyr based application to run on the LPC55S69.  The app is actually a pair of firmware projects, which at this time coordinate with one another via the Inter-Processor Mailbox (IPM) facility of the LPC55S69.  I'm having trouble finding, however, an application note or technical specification that describes how the two cores of the LPC55S69 get to access both static RAM and FLASH memory resources that are on chip.  Is there such an application note available from NXP?  Where may I find this?

I have searched the forum with various search phrases such as "dual-care memory arbitration" and "AHB memory arbitration", "shared memory access", and similar.  I've also search developer.arm.com for documents on the Advanced Hardware Bus (AHB) specification, and specifically bus arbiter.  I have not yet found a document describing whether there are, and what type of memory access rules are provided in the LPC55S69.  I specifically need to understand whether both cores are able to access the same memory location in the same clock cycle.  Seems unlikely, but I still need confirm there is a resource sharing arbitration in place.  This will allow me to proceed with the dual core application design work path which I am taking.

- Ted

[Alice_Yang]

Hello @tedhavelka1 

These demos are not about AHB, while if you want to use dual cores of lpc55s69, recommend refer to them.

The SDK support MCUXpresso , IAR , Keil, GCC ARM Embedded, it includes drivers and demos.

I take a video about how to download, you can have a look at my attachment.

BR

Alice

[tedhavelka1]

Hello Alice,

First, thank you for the fast reply to my technical inquiry!  I should have shared a little more context regarding my development tools and environment:  I'm fairly far into firmware development on the LPC55S69, using Zephyr's toolchain including `west`, cmake, a GCC cross-compiler and related tools.  I do not have MCUExpresso installed, nor have I been looking to go with any graphically enabled development environment.

Your screen shot highlighting dual-core samples gives me some specific demo applications to explore, so again thank you.  I have however already searched for some twenty minutes for the SDK you cite, and it's not obvious to me how it is named or whether it is bundled with an IDE.

Does NXP offer the SDK just as a set of sources and headers, a library and collection of compile-able software without development tools?

This type of download would be the most useful for me to review the demos and see whether they answer my question.  Though I will be surprised whether these demos go to the actual question of whether there is memory access arbitration at the hardware / silicon level of the LPC55S69.  That is really my original question.

I believe there must be some kind of memory access arbitration provided by whichever version of AHB or AHB-Lite is / are implemented in the LPC55S69 bus matrix.  But if by chance there is not, then I will carefully study the SDK demos for any software implementations of mutex or semaphores which coordinate dual-core apps and protect from race conditions.

Thank you ahead of time for what help you can offer navigating me to the SDK.  Let me know also if there is a better community forum here for the hardware related question I posed.  Sorry if I have posted to the wrong community forum!

- Ted

[tedhavelka1]

p.s.:  the closest code I have to NXP's SDK is that which ships with Zephyr RTOS 3.2.0.  I believe it's here at this github address:  https://github.com/zephyrproject-rtos/hal_nxp.

[Alice_Yang]

Hello @tedhavelka1 

There are dual cores demos under SDK, how about first have a look at these:

BR

Alice

[tedhavelka1]

Say I have tried multiple times now to download MCUXpresso v2.13.1 while logged into my NXP developer account.  The "download" button on NXP's site always goes to a page which asks me to select a board or kit.  When I select my board there is an update to the page regarding version of SDK, but no link or button to download, and no instruction or choice to move forward otherwise.  The page seems broken.  It is definitely not clear how to download any SDK from NXP's pages which are top NXP search results for "MCUXpresso SDK download".  Attached capture here shows page which provides no downward nor "next step" link: