topic Re: locate a function in RAM in CodeWarrior for MCU

locate a function in RAM

juliancox — Wed, 19 Jul 2017 22:36:01 GMT

I am still battling to implement a Write a byte in EEPROM. I know that the erase/program functions must be executed from RAM and several posts discuss moving a function into RAM. My question is - Can I specify a RAM address for the necessary functions so that they reside in RAM at build time and I don't have to move them - I can just call them in the normal way (assuming I first disable interrupts). Surely this would speed up overall execution time and reduce code size. If this is possible, how do I do it?

Re: locate a function in RAM

Alice_Yang — Thu, 20 Jul 2017 01:53:25 GMT

Hello julian,

I just want to know which product and which version of CW you used , if kinetis , please refer to this thread to relocate function to RAM:

https://community.nxp.com/docs/DOC-101433

Hope it helps

Alice

Re: locate a function in RAM

juliancox — Thu, 20 Jul 2017 15:47:35 GMT

I am using CW 10.7 and S08SH4 processor

Re: locate a function in RAM

ZhangJennie — Fri, 21 Jul 2017 02:14:57 GMT

Hi Julian

Yes, You can do it, please refer attached demo code. It was made under CW6.3 but it is easy to be imported to CW10.7.

Please refer S08_Flash.c, S08_Flash.h, main.c

Have a great day,
Jennie Zhang

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Re: locate a function in RAM

juliancox — Fri, 21 Jul 2017 08:32:22 GMT

Hi Jennie,

You forgot to attach the attachment!!!!

Re: locate a function in RAM

ZhangJennie — Sat, 22 Jul 2017 06:45:49 GMT

Hi Julian,

I did attached it. see:

Can't you see it? if not, please send me your email, I can send it to you. I just followed you. you can add me then send your email address with message.

Have a great day,
Jennie Zhang

Re: locate a function in RAM

juliancox — Sat, 22 Jul 2017 10:19:08 GMT

It eventually appeared. I think it was something to do with my browser (Safari)

Thanks.

Re: locate a function in RAM

juliancox — Mon, 31 Jul 2017 09:51:03 GMT

Hi Jennie,

Thanks for the help. I modified your project to remove the burst programming option (not needed) and changed the .prm file as I am using a SH4 chip, not a SH8. Everything worked fine so I copied the CopyTo Ram(), FlashInit() and FlashCmd() functions into my project. FlashInit() and CopyToRam() work fine, but it fails on Erase - does not return as expected. I think that something is getting corrupted in RAM, but at this stage I don't know whether it is the stack, the relocated FlashCmd() function or the variables. More work is needed. Two questions -

1. Do I need to disable interrupts during erase and program?

2. Can I debug the FlashCmd with the USBDM?

Regards

Julian

Re: locate a function in RAM

ZhangJennie — Wed, 02 Aug 2017 09:03:11 GMT

hi Julian,

Regarding to your questions

>>1. Do I need to disable interrupts during erase and program?

Yes, you do. Because erase/program can't be successfully if they are interrupted during the time.

>>2. Can I debug the FlashCmd with the USBDM?

yes. but please note we can't step over the FlashCmd code, it will destroy the erase/program time sequence.

Have a great day,
Jennie Zhang