Continuous Transmission Test Mode

This section describes how the radio transceiver can be forced to transmit single tone (CW continuous wave) and random signals (PRBS). This test mode can be used for RF related measurements (TX power, harmonics) and other test purposes. For further details refer to appendix A (Continuous Transmission Test Mode) of the AT86RF212 datasheet.

The sequences for continuous wave (CW) transmission using the High Data Rate Modes.

Parameters:

txdata

The data in this array define the generated test signal.
CW mode: If txdata consists of homogenuous values {0x00} or {0xff} and scramen=0, a single tone signal is generated:

txdata	mode	CW frequency
all bytes 0x00	O-QPSK_1000	fCH - 0.25 MHz
all bytes 0xFF	O-QPSK_1000	fCH + 0.25 MHz
all bytes 0x00	O-QPSK_400	fCH - 0.1 MHz
all bytes 0xFF	O-QPSK_400	fCH + 0.1 MHz

PRBS mode: A modulated RF signal is generated, if txdata consists of inhomogenous (random) values. If an IEEE 802.15.4 synchronization header (SHR: 0,0,0,0,0xA7) is included in the txdata array, the continuous transmission can be recognized by a receiver as a loop of individual IEEE 802.15.4 frames.

scramen {1} generate a PRBS signal (scrambler enabled), {0} generate a single tone signal (scrambler disabled).

submode {1} selects O-QPSK_1000 and $\pm$ 0.25 MHz distance to the channel frequency,
{0} chooses O-QPSK_400 and $\pm$ 0.1 MHz distance to the channel frequency

channel Current channel (fCH) to use for continuous transmission (see PHY_SET_CHANNEL).

txpower The power level index selected from table 7-15 (Recommended Mapping of TX Power, Frequency Band, and PHY_TX_PWR) of the AT86RF212 datasheet (see PHY_SET_TRANSMIT_POWER).

Note:: >> The data array txdata is written to the transceiver as PSDU data with the trx_frame_write() function, therefore it has a maximum length of 127 bytes.
>> Alternatively of using the IEEE channels, the continuous transmission test mode can also be used in conjunction with the user-defined RF channels.
>> Instead of using the register start method, also the pin start method can be used.

Use Cases:

PHY_CONT_TX_CW_REGSTART

This sequence describes the transmission of a continuous test signal. Depending on the parameter scramen a CW signal or a PRBS signal is generated.

Code example

    /* AT86RF212::TRX_OFF */
    trx_reg_write(RG_IRQ_MASK, TRX_IRQ_PLL_LOCK);
    trx_bit_write(SR_TX_AUTO_CRC_ON, 0);
    trx_bit_write(SR_CHANNEL, channel);
    trx_reg_write(RG_PHY_TX_PWR, txpower);
    trx_reg_write(0x36, 15);
    trx_bit_write(SR_BPSK_OQPSK, 1);
    trx_bit_write(SR_OQPSK_DATA_RATE, 3);
    trx_reg_write(RG_OQPSK_SCRAM_EN, scramen);
    trx_bit_write(SR_SUB_MODE, submode);
    trx_frame_write(len(txdata), txdata);
    trx_reg_write(RG_PART_NUM, 84);
    trx_reg_write(RG_PART_NUM, 70);
    trx_bit_write(SR_TRX_CMD, CMD_PLL_ON);
    delay(tTR4);
    /* AT86RF212::PLL_ON */
    trx_bit_write(SR_TRX_CMD, CMD_TX_START);
    /* AT86RF212::BUSY_TX */

PHY_CONT_TX_STOP

This sequence stops the Continuous Transmission Test Mode. It is recommended to perform a reset after stopping this mode (see also TRX_RESET).

Code example

    /* AT86RF212::BUSY_TX */
    trx_reg_write(RG_PART_NUM, 0);
    trx_pinset_reset(0);
    trx_pinset_slptr(0);
    delay(t10);
    trx_pinset_reset(1);
    delay(tTR13);
    /* AT86RF212::TRX_OFF */