[172] RADIO: Bluetooth Long Range co-channel performance

This anomaly applies to IC Rev. Engineering D, build codes CKAA-DA0, QIAA-DA0, QFAA-Dx0.

It was inherited from the previous IC revision Revision 1.

Symptoms

Packet loss when a blocker signal is present.

Conditions

Bluetooth Long Range (Ble_LR125Kbit or Ble_LR500Kbit). Blocker signal present at the same or nearby RF frequency.

Consequences

Fails Bluetooth test with co-channel interference (RF-PHY/RCV/BV-29-C) without firmware workaround.

Workaround

Workaround is incorporated into S140 SoftDevice v6.1.1 and the DTM example in SDK v15.3.0. See the following document for a description of the workarounds:

nRF52840 Errata Attachment Anomaly 172 Addendum The performances can be improved further by updating the RSSI calibration value with the following workaround supported in SoftDevice 7.2, 7.3, 8.0, and later:

void ftpan_172_func(void)
{
 *((volatile uint32_t *)0x4000154Cul) = 0x80000400ul;
}
 
//for SD7.2.0 
int main(void)
{
 //...
 sd_softdevice_enable(...);
 //...
 const struct { void (*ftpan_172_func_ptr)(void); } ftpan_172_func_struct = { ftpan_172_func };
 sd_ble_opt_set(BLE_GAP_OPT_BASE + 6, (const ble_opt_t *) &ftpan_172_func_struct);
 //...
}
 
//for SD8.x.x
int main(void)
{
 //...
 sd_softdevice_enable(...);
 //...
 const struct { void (*ftpan_172_func_ptr)(void); } ftpan_172_func_struct = { ftpan_172_func };
 sd_ble_opt_set(0xF2, (const ble_opt_t *) &ftpan_172_func_struct);
 //...
}