https://devzone.nordicsemi.com/f/nordic-q-a/23970/where-is-characteristic-value-data-keptHello, Is the characteristic value data supplied to sd_ble_gatts_characteristic_add() and sd_ble_gatts_value_set() copied into the softdevice RAM, or does the softdevice refer to application RAM whenever client requests a characteristic read? I cannoten-USTelligent Community 13Tue, 01 Aug 2017 10:52:41 GMThttps://devzone.nordicsemi.com/thread/94366?ContentTypeID=1Tue, 01 Aug 2017 10:52:41 GMT137ad170-7792-4731-bb38-c0d22fbe4515:c20e199e-ea6a-43c3-9300-94c4433e96dcKrzysztof Zaraska<p>Found it .</p> <p>It&#39;s defined by vloc field in ble_gatts_attr_md_t structure which is also passed to sd_ble_gatts_characteristic_add().</p> <p>Possible values are:</p> <p>#define BLE_GATTS_VLOC_STACK 0x01</p> <p>Attribute Value is located in stack memory, no user memory is required.</p> <p>#define BLE_GATTS_VLOC_USER 0x02</p> <p>Attribute Value is located in user memory. This requires the user to maintain a valid buffer through the lifetime of the attribute, since the stack will read and write directly to the memory using the pointer provided in the APIs. There are no alignment requirements for the buffer.</p><div style="clear:both;"></div>