How an application greater than 250KBytes can upload into nrf51822?

RE: How an application greater than 250KBytes can upload into nrf51822?

ashokraj — Thu, 24 Jan 2019 16:18:21 GMT

Hi Sigurd, I am fledging embedded systems engineer. I have not compiled the program. I have got from senior engineer and I have uploaded on to product. I have simply noticed it from computer properties.

RE: How an application greater than 250KBytes can upload into nrf51822?

awneil — Thu, 24 Jan 2019 11:28:05 GMT

[quote userid="8189" url="~/f/nordic-q-a/42934/how-an-application-greater-than-250kbytes-can-upload-into-nrf51822/167516"]If you load past physical FLASH, it will wrap around[/quote]

No, that's not true.

RE: How an application greater than 250KBytes can upload into nrf51822?

awneil — Thu, 24 Jan 2019 11:26:45 GMT

[quote userid="15146" url="~/f/nordic-q-a/42934/how-an-application-greater-than-250kbytes-can-upload-into-nrf51822/167591"]the size of the .hex is not the same as the flash usage[/quote]

Indeed - this is a common beginner's misconception!

In fact, the size of a hex file is over twice the size of the actual binary code that it represents!

This has nothing specifically to do with Nordic.

See, for example, http://www.keil.com/support/docs/3250.htm

https://en.wikipedia.org/wiki/Intel_HEX

RE: How an application greater than 250KBytes can upload into nrf51822?

Sigurd — Thu, 24 Jan 2019 10:17:09 GMT

Hi,

[quote userid="68734" url="~/f/nordic-q-a/42934/how-an-application-greater-than-250kbytes-can-upload-into-nrf51822"]I have an application of memory size 380Kbytes[/quote]

How are you measuring this? Note that the size of the .hex is not the same as the flash usage. The total flash usage is Code + RO-data + RW-data, these values are typically displayed after you have compiled your application.

RE: How an application greater than 250KBytes can upload into nrf51822?

natersoz — Thu, 24 Jan 2019 03:46:04 GMT

Check your linker options. In gcc-arm it is a .ld file:

MEMORY
{
FLASH (rx) : ORIGIN = 0x26000, LENGTH = 0x5a000
RAM (rwx) : ORIGIN = 0x20000000 + __SOFTDEVICE_DATA_SIZE, LENGTH = 64K - __SOFTDEVICE_DATA_SIZE
}

Something like that. You can upload anything you want if the linker file says it will fit.

That does not necessarily match reality. If you load past physical FLASH, it will wrap around. Nothing will actually work.

Make sure your linker file/settings match physical reality.