Enabling / Disabling I-Cache while Softdevice is Enabled on NRF52840

RE: Enabling / Disabling I-Cache while Softdevice is Enabled on NRF52840

peter9477 — Tue, 21 Mar 2023 17:45:33 GMT

I have no issue. If you read my comment, you can see I'm responding to an earlier comment with what I believed was useful information that might help others who may come along later to read this thread...

RE: Enabling / Disabling I-Cache while Softdevice is Enabled on NRF52840

Sigurd — Mon, 20 Mar 2023 12:28:46 GMT

Hi peter9477,

This case is ~4 years old. Please create a new case for the issue you are having. Make sure to include SDK, SoftDevice version, etc when you create a new case: https://devzone.nordicsemi.com/support/add

RE: Enabling / Disabling I-Cache while Softdevice is Enabled on NRF52840

peter9477 — Sun, 19 Mar 2023 23:45:58 GMT

I'm running with the S140 SoftDevice and the ICACHECNF value is 0x01. Since I didn't enable it, and the default value in that register is 0, according to the datasheet, that must mean the SoftDevice enabled it. That implies strongly that you can't disable it when running the SoftDevice, because it wouldn't know that you'd disabled it.... the state of the register would be identical to its value after a reset.

RE: Enabling / Disabling I-Cache while Softdevice is Enabled on NRF52840

donbosley — Tue, 15 Jan 2019 16:18:32 GMT

There are other posts that say it is, but I don't see it in the SD spec, so I'm not sure... I will try this and see what happens.

RE: Enabling / Disabling I-Cache while Softdevice is Enabled on NRF52840

Sigurd — Tue, 15 Jan 2019 13:29:05 GMT

Hi,

[quote userid="53848" url="~/f/nordic-q-a/42527/enabling-disabling-i-cache-while-softdevice-is-enabled-on-nrf52840"]Since SD engages it by default, I can't turn it off before I start SD. [/quote]

I don't think that is correct. If you disable it before you enable the SD, the SD should not enable it again.

So just call this before ble_stack_init():

NRF_NVMC->ICACHECNF = 0x00;