Simple Question About Memory Map and Region

[MANGO]

Hi, this is kind of a basic question.

So please forgive me if this is too easy...

This picture is from nRF51822_PS_3.1.pdf.

Also these pictures is from the nRF51_Series_Reference_manual v3.0.pdf

==1. The SRAM has the data.

Then what's inside the RAM where the address at 0x6000 0000 to 0xA000 0000 ?

If its has different things case by case, then what usually this RAM holds?

==2. The RAM where the address at 0x6000 0000 to 0xA000 0000, is a DRAM?

Or this RAM dropped a "S'?

==3. At the nRF51822_PS_3.1.pdf page 64, it says that

"The flash memory is organized in 256 byte rows starting at CODE and UICR start address.".

I use pstorage functions provided from the SDK 7.2 with SoftDevice S110.

When I save data using pstorage_store or pstorage_update function,

(skipping the cmd_queue stuffs)

the data are saved at "reserved" places in memory map in between

Code, FICR, and UICR?

Edited : Added Memory Screen when debugging

-Regards, Mango922

[RK]

1. Nothing. That picture is the generic Cortex-M0 diagram which shows the possible blocks on a Cortex-M0 system. The nrf51 manual shows what blocks are actually implemented. So there's nothing up at 0x60000000-0xA0000000.

2. The data is stored in the topmost flash pages of the CODE region, ie on 256k flash chips from 0x3fc00 or 0x3f800 or lower if you want more than a couple of kb of storages. Or if there's a bootloader installed at the top, just below that. pstorage comes out of your flash memory allocation.

[MANGO]

=1. Really? There's nothing? Can you tell me what page to look at the nrf51 manual?

Or do you mean the manual shows no information at that block?

=2. Hmm... You mean the System Address (maybe like 0x100010FF, the end of UICR) is mapped

to flash address 0x3FC00? Also, how did you know it is mapped to flash's address 0x3FC00?

+) One more thing. The RAM (addr : 0x60000000 ~) is a DRAM?

[RK]

1. No there is nothing there. You yourself posted the diagram from the product spec showing that area is 'reserved'. There is nothing there.

2. No I don't mean that at all and it's not what I said. You asked where data is stored when you use the pstorage functions and I told you it's stored at the end of flash memory, because it is. No system address isn't remapped, Flash is flash, UICR is UICR, they have the memory areas shown on the diagram, that's it. If you look at the pstorage code you will see it writes to the flash memory, directly, in the flash memory region from 0x00000000 to 0x0003ffff (or wherever your chip happens to have flash memory).

3. No the RAM address 0x60000000 is not a DRAM because there is nothing there, at all.

[MANGO]

Oh, thanks! At no. 1, I was quite confused that one picture was written "reserved"

but the other was written as "RAM". No wonder why the picture gave me confusion.

I have checked the sd_flash_write function at pstorage.c.

It calculates the page number, so you're right about writing directly at flash memory.

/********************/

Actually, my problem is that without using pstorage_load, I want to check the flash memory

directly when I'm debugging. I use IAR 7.1 and J-Link Edu.

I had a problem that when I call pstorage_load, it sometimes read other blocks instead.

So, in short, I can't check the flash memory

when I'm looking at the memory screen right?

(I'll add a picture about the "memory screen" at the question.)

Then is there a way to check the flash memory while debugging with IAR, J-Link Commander, or etc?

[RK]

That is how you check the flash memory while debugging, what makes you think the data shown there is incorrect? I seriously doubt that pstorage_load is reading 'other blocks instead'. Perhaps you should start back at the beginning and ask a new question about the problem you're actually having, with code and examples, then someone may be able to help you.