TMS320F280038-Q1: External flash memory on a custom embedded system

Silas Perry

Hello,

I am relatively new to the embedded system development world and I was wondering if I could in theory use external ROM on a custom board for the above specified processor in order to run RTOS. I need about 4Mbytes of memory ideally. If this is possible, are there any external memory devices that you would recommend i use?

Furthermore, assuming I understand all the other needed circuitry, would I be able to use the corresponding launchpad's linker device to program this custom board?

Lastly, how many bits does the external flash memory need to use? Can i use external flash memory with internal RAM?

thanks,

-Silas Perry

over 1 year ago

0 Omer Amir over 1 year ago

TI__Mastermind 30185 points

Hello Silas,

Silas Perry said:
Furthermore, assuming I understand all the other needed circuitry, would I be able to use the corresponding launchpad's linker device to program this custom board?

As long as you have some JTAG connection or other serial connection for programming Flash, then yes it should be possible. I recommend taking a look at the Programmers and Debuggers section of the C2000 Getting Started guide.

I will check on your other two questions and get back to you.

Best regards,

Omer Amir

0 Omer Amir over 1 year ago

TI__Mastermind 30185 points

Hi Silas,

It looks like you listed F28003x as the device for this thread, but unfortunately there is no EMIF peripheral for this device (External Memory Interface). If you want a device with this peripheral to interface with Flash, EMIF does support interfacing with external NOR Flash but you will need to use a device like the F2838x to have this capability. Otherwise, you will need to create your own drivers for F28003x to interface with external memory (although this will be highly software intensive).

Silas Perry said:
If this is possible, are there any external memory devices that you would recommend i use?

As far as what external memory devices you should use, this is up to you and your application. You can look at the EMIF to determine what limitations you have regarding access timing, size, etc. You can refer to the Design and Usage Guidelines for the C2000 EMIF for more information (see section 2 Memory Selection).

Silas Perry said:
Lastly, how many bits does the external flash memory need to use? Can i use external flash memory with internal RAM?

The EMIF allows you to access 16-bit or 32-bit words, and it is accessibly program-wise by a pointer to the memory location mapped via the CPU. You can refer to the device data sheet for what memory ranges these are (below is an example for the F2838x):

Best regards,

Omer Amir

0 Silas Perry over 1 year ago in reply to Omer Amir

Prodigy 105 points

Hello Mr. Amir,

I have a follow up question on this. Assuming I change the device to the F2838x, does that mean i can address memory up to 32-bit? The datasheet for this chip says it can address 32 bit through EMIF1. In that case, can you please let me know if it is possible to interface to this NOR flash chip? https://www.mouser.com/ProductDetail/Micron/MT25TL01GBBB8ESF-0AAT?qs=sGAEpiMZZMtLtwjrIQVJ5joXWQlLhvyQbASuk5nRFFqAzu264ru87g%3D%3D. Thanks!

0 Vivek Singh over 1 year ago in reply to Silas Perry

TI__Guru** 115271 points

Are you referring to 32bit address space ? If yes, then no, Omer has shared the the memory map which is accessible via EMIF interface.

0 Silas Perry over 1 year ago in reply to Vivek Singh

Prodigy 105 points

Hello, can you please point me to a chip set that would work for external flash memory? I want to add code space to the F2838x controller that I am embedding.

0 Silas Perry over 1 year ago in reply to Vivek Singh

Prodigy 105 points

I don't understand why the 1 gig external memory would not work. That memory map seems to say that I could address 256M X16. Can you help me understand why I could not use the chip i mentioned?

0 Vivek Singh over 1 year ago in reply to Silas Perry

TI__Guru** 115271 points

That is for SDRAM interface and not ASRAM interface. Both are different interface.

0 Silas Perry over 1 year ago in reply to Vivek Singh

Prodigy 105 points

I don't want external RAM. Can you please point me to external NOR flash ROM that i could use for external memory on the the C2838x?

0 Vivek Singh over 1 year ago in reply to Silas Perry

TI__Guru** 115271 points

I see that the part you have selected also support SPI interface. Is that something you can use ?

0 Silas Perry over 1 year ago in reply to Vivek Singh

Prodigy 105 points

Yes I do have access to SPI. However, the C2838X series has EMIF units on the chip. I think those would be able to send data faster because it would be in parallel on a bus and not serially over SPI lines. Can you please point me to a external NOR ROM flash memory chip that I could connect to the EMIF interface?

0 Vivek Singh over 1 year ago in reply to Silas Perry

TI__Guru** 115271 points

You can try -

S29AL016J70TFI020

Also refer this appnote for more detail.

Vivek Singh

C2000™︎ microcontrollers

C2000 microcontrollers forum

TMS320F280038-Q1: External flash memory on a custom embedded system

S29AL016J70TFI020