Radio Constants

This section contains AT86RF231 specific constants.

• General Constants
• Radio Specific Timer Constants
• General Timer Constants
• Rate dependant Timer Constants

General Constants

Symbol	Comment	Unit	Typical Value
RSSI_BASE_VAL	The minimum RSSI level	dBm	-91

Timer Constants

Radio Specific Timer Constants

The timings in the table below refer to table 7.1 (State Transition Timing) and section 12.4 (Digital Interface Timing Characteristics) of the AT86RF231 datasheet.

Symbol	Comment	Unit	PHY-Mode
			O-QPSK_250
t7	SLP_TR pulse width	ns	62.5
t8	SEL rising to falling edge; SPI read/write, standard SRAM and frame access modes; idle time between consecutive SPI accesses	ns	250
t8a	SEL rising to falling edge; Fast SRAM read/write access mode, refer to section 9.1.5; idle time between consecutive SPI accesses	ns	500
t9	SCLK rising edge LSB to /SEL rising edge	ns	250
t10	Reset pulse width	ns	625
t12	AES core cycle time	µs	24
tTR1	State transition from P_ON until CLKM is available	µs	380
tTR2	State transition from SLEEP to TRX_OFF	µs	240
tTR3	State transition from TRX_OFF to SLEEP	CLKM cycles	35
tTR4	State transition from TRX_OFF to PLL_ON see AT86RF231 datasheet, table 7.1 (State Transition Timing)	µs	110
tTR5	State transition from PLL_ON to TRX_OFF	µs	1
tTR6	State transition from TRX_OFF to RX_ON see AT86RF231 datasheet, table 7.1 (State Transition Timing)	µs	110
tTR7	State transition from RX_ON to TRX_OFF	µs	1
tTR8	State transition from PLL_ON to RX_ON	µs	1
tTR9	State transition from RX_ON to PLL_ON	µs	1
tTR10	State transition from PLL_ON to BUSY_TX	µs	16
tTR12	Transition from all states to TRX_OFF	µs	1
tTR13	State transition from RESET to TRX_OFF	µs	37
tTR14	Transition from all states to PLL_ON	µs	1
tTR15	Frame buffer emty indicator latency	ns	215
tTR16	FTN calibration time	µs	25
tTR17	DVREG settling time	µs	60
tTR20	PLL settling time on channel switch	µs	11
tTR21	PLL CF calibration time	µs	35
tTR25	RSSI update interval	µs	2
tTR26	ED measurement time	µs	128 @ 250kb/s 32 @ High data rate mode during frame reception
tTR27	Minimum time to synchronize to a preamble and receive an SFD	µs	96
tTR28	CCA measurement time	symbol	8
tTR29	SR_RND_VALUE update time	µs	1

General Timer Constants

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

Symbol	Comment	Unit	Typical Value
tTRSw	Duration of a state change from [PLL_ACTIVE] to TRX_OFF, see table 7.1 (State Transition Timing) of the AT86RF231 datasheet.	-	see tTR5 and tTR7
tproc	Maximum internal processing delay for CCA and ED measurements.	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	= 545 @ normal_ack, unslotted mode >= 465 @ normal_ack, slotted mode = 385 @ short_ack, unslotted mode >= 465 @ short_ack, slotted mode
tFrame	Transmission duration of a frame with PHR field and maximum length PSDU ((1 + 127) * toct)	ms	4.096
tPSDU	Maximum transmission time of a PSDU (127* toct)	ms	4.064
tED	Duration of an manually started ED measurement tproc + tTR26	µs	140 @ Low Data Rate Mode 44 @ High Data Rate Mode
tReadED	Duration between TRX_IRQ_RX_START and end of ED measurement when receiving a frame tproc + tTR26 - toct	µs	108 @ Low Data Rate 28 @ 500 kb/s 36 @ 1 Mb/s 40 @ 2 Mb/s
tHED	Minimum time an ED measurement is valid (Minimum time for frame synchronization and minimum duration of an ED measurement) tTR27 + tTR26 + tproc	µs	236 @ Low Data Rate Mode 140 @ High Data Rate Mode
tSHR	Transmission time of SHR 5*toct	µs	160
tWaitAck	Time between end of a frame reception and start of the acknowledgment transmission aTurnaroundTime = 12 * tsym	µs	192
tAckDone	Time between end of a frame reception and end of the acknowledgment transmission unslotted mode: 34*tsym slotted mode: t9 + tSlWait + tTR10 + 22 * tsym	µs	= 544 @ normal_ack, unslotted mode >= 464 @ normal_ack, slotted mode = 384 @ short_ack, unslotted mode >= 464 @ short_ack, slotted mode
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 >= 6 @ 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 @ normal_ack 2 @ short_ack

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 7.2.3.3 (Configuration of non IEEE Compliant Scenarios) of the AT86RF231 datasheet).

Rate dependant Timer Constants

Data Rate	tSYM[1] / µs	tOCT[2] / µs	tPHR[3] / µs	tSHR[4] / µs
250 kb/s	16	32	32	160
500 kb/s	8	16	32	160
1 Mb/s	4	8	32	160
2 Mb/s	2	4	32	160

Note:

• The data rates O-QPSK_{500,1000,2000} 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 of an PSDU octet.
• [3] This parameter defines the duration the PHR field.
• [4] This parameter defines the duration of SHR and PHR.

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