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CC256x Testing Guide

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Device Power Up

Required Voltage Rail and Signal Sequence

Proper power up of the device:

  1. nSHUTDOWN must be low.
  2. Turn on power supplies:
    1. Turn on VDD_IN (3.3V, max range is 1.8V to 4.8V)
    2. Turn on VDD_IO (1.8V, max range is 1.62V to 1.92V)
    3. VDD_IO and VDD_IN must be stable before releasing nSHUTDOWN.
  3. Slow Clock must be stable within 2ms of releasing nSHUTDOWN.
  4. Fast Clock must be stable within 20ms of releasing nSHUTDOWN.
  5. The CC256x device will indicate a complete proper power-up sequence by pulling HCI_RTS low.

Power up sequence.jpg
Figure: Proper Power Up Sequence

No signals are allowed on the I/O pins if VDD_IO power is not present.  
The only exceptions on this are the SLOW_CLK, XTALP, XTALM, and AUD_xxx pins that are fail-safe and can tolerate external voltages without VDD_IO and VDD_IN present.


The nSHUTDOWN initializes a boot-up of the CC256x device, after the power rails have been applied. The device signals that a proper boot-up was performed by pulling HCI_RTS low.

UART Communication

The 4-wire UART connection (H4) has the following default settings:

  • 115.2 kbps baudrate
  • Hardware (HW) flow control
  • UART 8N1 setting:
    • 8-bits
    • No parity bit
    • 1 stop bit

An example of UART HCI communication:
Outgoing command: HCI_Read_Local_Version_Information
Outgoing Hex dump: 0x01 0x01 0x10 0x00
where the first number indicates a command sent (0x01), the second number (0x01) and third number (0x10) is the command opcode and fourth indicates parameter length

Incoming Hex dump: 0x04 0x0e 0x0c ......
where the first number (0x04) indicates an event received, the second number (0x0e) indicates the type of event, and the rest of the numbers is the event.

It is not necessary to download the service pack to verify UART communication with the example above.

Device Initialization Procedure

The service pack (SP) download procedure:

  • Is done right after device power-up sequence.
  • Must be done after every power cycle.
  • Is done before any BT RF testing.
  • Must be done before any BT operations such as Inquiry, Page or connections

Bootup sequence.jpg
Figure: Device Initialization Sequence

Basic BT Operations

  • Service pack must have been loaded.
  • Examples of basic BT operations:
    • Inquiry: The CC256x device is looking for other BT devices that are nearby.
    • Inquiry Scan: The CC256x device is visible but not connectable (it has discoverable MAC address).
    • Page Scan: The CC256x device is connectable but not visible (can accept connections).

Basic BT Operation.jpg
Figure: Example of Bluetooth Inquiry Operation


The Bluetooth RF FCC modes are connection-less RF spectrum tests which uses a spectrum analyzer for verification.

Note: The CC256x device must be power cycled when switched between different FCC modes. Please also note that the initscript must be downloaded to the CC256x device after each power cycle before performing the next test.

Continuous TX

This is a non-packet continuous transmission with either CW(Continuous Wave), GFSK (BR), π/4-DQPSK (2-EDR) or 8DPSK (3-EDR).
The HCI commands to put the device in the constant TX mode (after service pack has been loaded) are:

HCI_VS_DRPb_Tester_Con_TX 0xFD84, 0x1, 0, 0, 15, 0x00000000, 0x00000000

HCI_VS_Write_Hardware_Register 0xFF01, 0x0019180c, 0x0101

HCI_VS_DRPb_Enable_RF_Calibration 0xFD80, 0xFF, 0xFFFFFFFF, 0x01

The parameters for the HCI_VS_DRPb_Tester_Con_TX can be found here.

NoteNote: The second and third commands are for internal settings (HCI_VS_Write_Hardware_Register and HCI_VS_DRPb_Enable_RF_Calibration ). The HCI_VS_Write_Hardware_Register 0xFF01, 0x0019180c, 0x0101 command is only required for the continuous TX test of modulated (GFSK, π/4-DQPSK or 8DPSK) signal. This command should be skipped when performing continuous TX test for CW.

BT RF FCC modes.jpg
Figure: Typical test setup for Continuous TX mode.

NoteNote: It is recommended to use the HCITester tool on the PC to send the HCI commands to the CC256x device. The HCITester can be downloaded as part of the Wireless Tools package.

Packet TX/RX

To enable the continuous packet transmission/receive the following command needs to be sent after the loading of the service pack:

HCI_VS_DRPb_Tester_Packet_TX_RX 0xFD85, 0x03, 0, 0xFF, 0, 2, 0, 27, 15, 1, 0x01FF

The parameters for the HCI_VS_DRPb_Tester_Packet_TX_RX can be found here.

NoteNote: By default, the device uses all the 79 channels in frequency hopping mode. To reduce the number of channels, the following commands should be executed prior to HCI_VS_DRPb_Tester_Packet_TX_RX.

  • Enable Local AFH Assessment
HCI_Write_AFH_Channel_Assessment_Mode 0x1 
  • Classify Channels to Reduce Hopping Scheme

Bad Channel = 1, Unknown Channel = 0
<ChannelMap> = B0B1B2B3B4B5B6B7B8B9
Bx = b7b6b5b4b3b2b1b0
Chx = bx
Freq = 2402 + Chx
e.g. <ChannelMap> = '000000E0FFFF01000000', Blocked Channels = 0 - 28 and 49 - 78, Used Frequencies = 2,431MHz - 2,450MHz

HCI_Set_AFH_Host_Channel_Classification <ChannelMap> 

BT RF FCC modes.jpg
Figure: Typical test setup for Continuous TX mode

Continuous RX

To turn on the receiver portion of the chip the following command needs to be sent after the loading of the service pack:

HCI_VS_DRPb_Tester_Con_RX 0xFD17, 0, 0x00

The parameters for the HCI_VS_DRPb_Tester_Con_RX are:

  1. Op code (0xFD17)
  2. Frequency index (0-39: f=2402+(2*i)MHz, 40-78: f=2403+2(i-40)MHz)
  3. Internal setting (0x00)

The setup would be the same as for Continuous TX


The BT RF SIG mode is meant for connecting with a Bluetooth tester where the CC256x is controlled over the LMP (Link Management Protocol). The procedure for enabling the CC256x for BT SIG mode is:

  1. Proper device power-up
  2. Load the correct service pack
  3. Load the DUT script (three HCI commands)

Once the device (DUT) is in test mode, the BT tester will, through the RF connection (LMP), take control of the DUT.

BT RF SIG mode.jpg
Figure: CC256x Bluetooth RF SIG mode test setup

The HCI commands to put the device in test RF SIG mode are:

HCI_Set_Event_Filter 0x02, 0x00, 0x03

HCI_Write_Scan_Enable 0x03


This script will make the device visible and connectable (HCI_Set_Event_Filter ), auto-accept all connections (HCI_Write_Scan_Enable ) and put the DUT in test mode (HCI_Enable_Device_Under_Test_Mode). Once the proper sequence has been completed (first loading the BT service pack and then the DUT script), then the BT tester will take control of the device through the RF link (LMP).

Production Line Test (PLT)

See CC256x Production Line Testing Guide.

BLE Testing

This section provides information on how to configure the CC2564 device for the Bluetooth Low Energy (BLE) SIG RF PHY Testing.

The DUT is the CC2564 dual-mode Bluetooth device (possibly interfaced with host MPU/CPU). The Upper Tester is the PC which communicates with the DUT by sending HCI commands using UART 8-N-1 serial protocol. The DUT is also connected to the lower tester which is the Bluetooth tester (such as CBT Tester) via a U.FL/SMA connector.

Source: BT SIG CORE V4.0

Transmitter Test

The Bluetooth device will transmit to the Bluetooth tester which will analyze the power spectrum of the received data.

Figure 1. Transmitter Test, Source: Core V4.0

1. Initialize CC2564 device

 Load Core BT Service Pack (BT SP)to the CC2564 device 
Download Core BT SP

2. Enable BLE mode

NoteNote: If the CC256x Service Pack (SP) version contains a BLE add-on SP, then the HCI_VS_LE_Enable 0xFD5B command is embedded inside the BLE add-on SP and must not be sent again.
If the CC256x Service Pack (SP) version contains a BLE add-on SP:
 Load BLE Add-On SP 
Download BLE Add-On SP
 Execute the ''HCI_VS_LE_Enable 0xFD5B, 1, 1'' command 

3. Set the BLE Test Parameters

NoteNote: Power Level 1 is used for BLE. For more information on this command, refer to the CC256x_VS_HCI_Commands wiki
HCI_VS_Set_LE_Test_Mode_Parameters 0xFD77, 0x01, 0x0, Packets to transmit, Access Code, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00000000 
Command Parameter Size (bytes) Value Description
Packets to transmit 2



Unlimited - Continuous TX

N number of packets to transmit [1]
Access code 4 0xXXXXXXXX
An access code to sync and transmit
Default = 0x71764129 (TestMode AC)
  1. NoteNote: If the Packets to transmit is a specific value (i.e. Non-continuous), then the HCI_BLE_Transmitter_Test 0x201E must be sent twice. For more information, refer to the following E2E post

4. Start TX test [1]

HCI_BLE_Transmitter_Test 0x201E, TX_Channel , Data_Length, Payload_Type 
Command Parameter Size (bytes) Value Description
TX_Channel 1 0 - 39
TX Frequency: 2402 + 2*k,
where k is the channel (max val is 39)
Data_Length 1 0 - 37 (0x025)
Packet payload length up to 37 (0x25) bytes
Payload_Type 1 0 - 7
0 - PRBS9
1 - FOFO
2 - ZOZO
3 - PRBS15
4 - All Ones
5 - All Zeros
6 - OFOF
7 - OZOZ

5. Take measurements

Look at the Bluetooth tester results.

6. End BLE TX Test

HCI_BLE_Test_End 0x201F
NoteNote: To re-start transmission, go back to steps 3 (optional) and 4.

Receiver Test

The Bluetooth device will receive data from CBT and PC will calculate PER and BER from received data. 

Source: Core V4.0

1. Enable BLE mode:

HCI_VS_LE_Enable 0xFD5B, 1, 1

2. Set the type of test to run

PER_nBER = 1 (PER=1 or BER=0)

3. Set here the number of packets the tester transmits for PER measurements

Tx_Packets = 1500

4. Set RX Frequency Channel 2402 + 2*k, where k is the channel (max val is 39)

RX_Channel = 0 (same as k)

5. Set the RX Mode According to the options below (Default is "1"):
# 0 - Normal mode, Open loop & no power saving
# 1 - Wide window mode, Close loop & no power saving
# 2 - Continuous RX, Open loop before SYNC
# 3 - Wide window & power saving mode, Close loop & power saving

RX_Mode = 1

6.Set the RX Access Code to Sync on (Default is 0x71764129)

RX_AC = 0x71764129

7. Set paylaod type
# 0 - PRBS 9
# 1 - FOFO
# 2 - ZOZO
# 3 - PRBS 15
# 4 - All Ones
# 5 - All Zeros
# 6 - OFOF
# 7 - OZOZ

PayloadType = 0x00

8. Set length of packet fields in Bytes

Header_Length = 2
Payload_Length = 37
CRC_Length = 3

9.Set CRC for PRBS9 with 37 Bytes length

CRC_Value = 0x00E221E8

10. When traces are enabled than the Cortex is not able receive the next packet

En_Traces = 0

11. Set the amount of bad bits/packet to identify FA (in percent) and set Enable_BER

FA_THR_inPer = 7
Total_Bits_in_packet = 8 * (Header_Length + Payload_Length + CRC_Length)
FA_THR_inBits = round((FA_THR_inPer/100) * Total_Bits_in_packet)

if (PER_nBER == 1) then
	Enable_BER = 0
	Enable_BER = 1

12. Clear Sync Counter

HCI_VS_Write_Hardware_Register 0xFF01, 0x0019324E, 0x0
Outgoing Dump: 01 01 ff 06 4e 32 19 00 00 00
Incoming Event: 04 0e 04 01 01 ff 00 (Command Complete Event)

13. Update Parameters

HCI_VS_Set_LE_Test_Mode_Parameters 0xFD77, 0x01, RX_Mode, 0, RX_AC, Enable_BER, PayloadType, Payload_Length, FA_THR_inBits, En_Traces, CRC_Value
HCI_VS_Set_LE_Test_Mode_Parameters 0xFD77, 0x01, x01, 0x0000, 0x71764129(RX_AC), 0x00(Enable_BER), 0x00(PayloadType), 0x25(Payload_Length), 0x18(FA_THR_inBits), 0x00(En_Traces), 0x00E221E8

14. Start RX Scan

HCI_BLE_Receiver_Test 0x201d, RX_Channel

Pause here and send data packets from the CBT Tester. Continue with scripts after sending all the packets.  

15. If testing for PER:

if (PER_nBER == 1) then
	HCI_BLE_Test_End 0x201f

Returns number of packets recieved, save into &Rx_Packets.

16. Read Phy - Sync Counter Value

HCI_VS_Read_Hardware_Register 0xFF00, 0x0019324E
Outgoing Dump: 01 00 ff 04 4e 32 19 00
Incoming Event: 04 0e 06 01 00 ff 00 0a 00 (Command Complete Event, Value: 0x000A)

Returns Sync Counter Value, save into &Sync_Counter.

17. Calculate PER = 100*(Tx_Packets - Rx_Packets)/Tx_Packets

18. For BER:

HCI_BLE_Test_End 0x201f

Returns number of packets recieved, save into &Rx_Packets.

19.Read BER Results

Hci_VS_LE_Read_Ber_Test_Results 0xFDAE

Vendor-Specific LE_Read_Ber_Test_Results Command Complete parameters:

See in wiki.

20. Read Phy - Sync Counter Value

HCI_VS_Read_Hardware_Register 0xFF00, 0x0019324E
Outgoing Dump: 01 00 ff 04 4e 32 19 00
Incoming Event: 04 0e 06 01 00 ff 00 0a 00 (Command Complete Event, Value: 0x000A)

Returns Sync Counter Value, save into &Sync_Counter.

21. Calculate Actual Syncs

Actual_Syncs = BER_Syncs - FA_Events

22. Calculate BER:

# Bit Counters
Total_Bad_Bits = Htype_Bad_Bits + Hlength_Bad_Bits + Ppart1_Bad_Bits + Ppart2_Bad_Bits + Ppart3_Bad_Bits + Ppart4_Bad_Bits + CRC_Bad_Bits
Dropped_Packets = Actual_Syncs - Total_Good_Packets
Detected_Packets = Actual_Syncs
Total_Received_Bits = Total_Bits_in_packet * Detected_Packets

if(Total_Received_Bits == 0) then
BER = 100
BER = 100*(Total_Bad_Bits / Total_Received_Bits)

Related Documents

  • Cite error: Invalid <ref> tag; no text was provided for refs named Number_Of_Packets