nRF51822 Memory map

[roger.k]

Hi. I'm using nRF51822AC, SDK12.2.0, S130. The size of "s130_nrf51_2.0.1_softdevice.hex" in SDK is almost 300KB. But chip's flash mem size is just 256KB. It's bigger than flash. How can it be possible to download?

Q1. The real size has different file size? How can I estimate the size of Soft device?

And example code size(ble_app_uart_pca10028_s130.hex) is 335KB.

Q2. How can I estimate the real size of application if it's not real flash size?

Q3. Can you check if my Keil setting is OK or not as below?

I need your help.

[Jørgen Holmefjord]

Hi,

The size of the HEX file is not the size used in flash. You can read more about the Intel HEX format here. The softdevice memory usage is described in the softdevice documentation.

You can find a tutorial about RAM and ROM management here. This should answer Q2 and Q3.

Best regards,

Jørgen

[roger.k]

Thank you for your help. The nordic blog as below.

devzone.nordicsemi.com/.../

S130 v2.0 from SDS v2.0 •IRAM base - 0x20001870 •IRAM size(16 kB RAM) - 0x2790 •IRAM size(32 kB RAM) - 0x6790 •IROM base - 0x1B000 •IROM size(128 kB Flash) - 0x5000 •IROM size(256 kB Flash) - 0x25000

But it doesn't work when I change IRAM values to 0x20001870 and 0x6790. I'm using nRF51822AC S130 V2.0.1. What could be the problem?

I need your help.

[Jørgen Holmefjord]

The default values from the ble_app_uart_pca10028_s130 example project use these settings:

IROM1: START = 0x1b000, SIZE = 0x25000
IRAM1: START = 0x20001fe8, SIZE = 0x6018

[roger.k]

Thanks a lot for your reply. I'm using "ble_app_multilink_central". This example shows me memory map as below.

IROM1: START = 0x1b000, SIZE = 0x25000 IRAM1: START = 0x20005040, SIZE = 0x2fc0

That means RAM size for SD is 20KByte and RAM size for app is just 12KByte. Is it right? Isn't there any way to extend Memory? Because i face the problem of RAM size.

I need your help.

[Jørgen Holmefjord]

Please see this answer. If your application needs all 8 connections, you will have to optimize your code or move to a device with more RAM, e.g., nRF52832 (64 kB) or nRF52840 (256 kB).