Radio Constants

This section contains AT86RF212 specific constants.

• RSSI Base Value
• Radio Specific Timer Constants
• General Timer Constants
• Rate dependant Timer Constants

RSSI Base Value

The value RSSI_BASE_VAL itself depends on the PHY mode, as described in section Physical Layer Mode and table 6-25 (RSSI_BASE_VAL) of the AT86RF212 datasheet.

PHY Mode	RSSI_BASE_VAL (const.)
BPSK_20	RSSI_BASE_VAL_BPSK_20
BPSK_40	RSSI_BASE_VAL_BPSK_40
O-QPSK_100	RSSI_BASE_VAL_OQPSK_100
O-QPSK_250 (for SIN and RC-0.8 pulse shaping)	RSSI_BASE_VAL_OQPSK_250

Timer Constants

Radio Specific Timer Constants

The timings in the table below refer to table 5.1 (State Transition Timing) and section 10.4 (Digital Interface Timing Characteristics) of the AT86RF212 datasheet.

Symbol	Comment	Value
t7	SLP_TR pulse width	62.5 ns
t8	SPI idle time: SEL rising to falling edge	250 ns
t8a	SPI idle time: SEL rising to falling edge	500 ns
t9	SCLK rising edge LSB to /SEL rising edge	250 ns
t10	Reset pulse width	625 ns
t12	AES core cycle time	24 µs
t13	Dynamic frame buffer protection: IRQ latency	750 ns
tTR1	State transition from P_ON until CLKM is available	330 µs
tTR2	State transition from SLEEP to TRX_OFF	380 µs
tTR3	State transition from TRX_OFF to SLEEP	35 CLKM cycles
tTR4	State transition from TRX_OFF to PLL_ON	110 µs
tTR5	State transition from PLL_ON to TRX_OFF	1 µs
tTR6	State transition from TRX_OFF to RX_ON	110 µs
tTR7	State transition from RX_ON to TRX_OFF	1 µs
tTR8	State transition from PLL_ON to RX_ON	1 µs
tTR9	State transition from RX_ON to PLL_ON	1 µs
tTR10	State transition from PLL_ON to BUSY_TX	1 symbol
tTR12	Transition from all states to TRX_OFF	1 µs
tTR13	State transition from RESET to TRX_OFF	26 µs
tTR14	Transition from various states to PLL_ON	1 µs
tTR16	FTN calibration time	25 µs
tTR20	PLL settling time on channel switch	11 µs
tTR21	PLL CF calibration time	8 µs
tTR25	RSSI update interval	32 µs : BPSK20 24 µs : BPSK40 8 µs : OQPSK
tTR26	ED measurement time	8 symbol : Low Data Rate Mode (LDRM) and manual measurement in High Data Rate Mode (HDRM) 2 symbol : automatic measurement in High Data Rate Mode (HDRM)
tTR28	CCA measurement time	8 symbol
tTR29	SR_RND_VALUE update time	1 µs
tMSNC	Minimum time to synchronize to a preamble and receive an SFD	2 symbol

General Timer Constants

Timing constants which are not listed in the datasheet can be found in the table below.

Symbol	Comment	Unit	PHY-Mode
			BPSK_20	BPSK_40	O-QPSK_100	O-QPSK_250
tTRSw	Duration of a state change from [PLL_ACTIVE] to TRX_OFF, see table 5.1 (State Transition Timing) of the AT86RF212 datasheet.	-	see tTR5 and tTR7
tproc	Maximum internal processing delay for CCA and ED measurments.	µs	12
tLockCrit	Time until TRX_IRQ_PLL_LOCK should occur after a TRX_IRQ_PLL_UNLOCK	µs	32
tPAck	Processing time for transmitting an Acknowledgment, which arises from tTR8 + tAckDone	µs	5001	2501	1361	545
tFrame	Transmission duration of a frame with PHR field and maximum length PSDU ((1 + 127) * toct)	ms	51.2	25.6	10.24	4.096
tPSDU	Maximum transmission time of a PSDU (127* toct)	ms	50.8	25.4	10.16	4.064
tED	Duration of an manually started ED measurement tproc + 8*tsym @ Low Data Rate Mode tproc + 2*tsym @ High Data Rate Mode	µs	412	212	332	140
tReadED	Duration between TRX_IRQ_RX_START and end of ED measurement when receiving a frame tproc + 8*tsym - toct @ Low Data Rate Mode tproc + 2*tsym - toct @ High Data Rate Mode	µs	12	12	252	108
tHED	Minimum time an ED measurement is valid (Minimum time for frame synchronization and minimum duration of an ED measurement) t<sub>MSNC</sub> + 8*tsym + tproc @ Low Data Rate Mode t<sub>MSNC</sub> + 2*tsym + tproc @ High Data Rate Mode	µs	512	262	412	172
tSHR	Transmission time of SHR 5*toct	µs	2000	1000	400	160
tWaitAck	Time between end of a frame reception and start of the acknowledgment transmission aTurnaroundTime = 12 * tsym	µs	600	300	480	192
tAckDone	Time between end of a frame reception and end of the acknowledgment transmission unslotted mode BPSK: 100*tsym unslotted mode O-QPSK: 34*tsym slotted mode: t9 + tSlWait + tTR10 + 22 * tsym	µs	5000	2500	1360	544
			>=4750.25 @ normal_ack >=4600.25 @ short_ack	>=2375.25 @ normal_ack >=2300.25 @ short_ack	>=1160.25 @ normal_ack >=1040.25 @ short_ack	>=464.25 @ normal_ack >=416.25 @ short_ack
tSlWait	Time between end of a frame reception and start of the acknowledgment transmission in slotted operation mode, which depends on the next slot boundary. The given value is the minimum time between the TRX_IRQ_TRX_END interrupt and the rising edge of the pin TRX_PIN_SLP_TR.	symbol	>= 6 @ normal_ack >= 3 @ short_ack
tBEDead	Timeout counter to avoid deadlock for frame buffer empty indicator.	µs	64
tTxAck	Acknowledgement turnaround time from TRX_IRQ_TRX_END interrupt to the start of the acknowledgement frame transmission.	symbol	12

Parameters:

	normal_ack	normal timing for acknowledgement frame SR_AACK_ACK_TIME=0
	short_ack	short timing for acknowledgement frame SR_AACK_ACK_TIME=1 (see section 5.2.3.3 (Configuration of non IEEE Compliant Scenarios) of the AT86RF212 datasheet).

Rate dependant Timer Constants

PHY Mode	Data Rate	tSYM[1] / µs	tPHR[2] / µs	tOCT[3] / µs	tHEADER[4] / µs
BPSK_20	20 kBit/s	50	400	400	2400
BPSK_40	40 kBit/s	25	200	200	1200
O-QPSK_100	100 kBit/s	40	80	80	480
O-QPSK_200	200 kBit/s	40	80	40	480
O-QPSK_400	400 kBit/s	40	80	20	480
O-QPSK_250	250 kBit/s	16	32	32	192
O-QPSK_500	500 kBit/s	16	32	16	192
O-QPSK_1000	1000 kBit/s	16	32	8	192

Note:

>>  The data rates O-QPSK_{200,400,500,1000} are not compliant to the IEEE 802.15.4 standard.
>>  [1] This parameter defines the duration of a symbol.
>>  [2] This parameter defines the duration the PHR field.
>>  [3] This parameter defines the duration of an PSDU octet.
>>  [4] This parameter defines the duration of SHR and PHR.