Smart Reduced Power Consumption Techniques
Contents
1. Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote 082014 Figure 2 4 State Change from TRX_OFF to RX_ON with RPC Disabled Zoom Factor 40kX Zoom Position 31 75 AVDD regulator PES Mode ramping and PLL power saving TRX_OFF state Calibration disabled RX PN state ao OS ee Value Mean Min Max Std Dev 100 s 500kS s 3 JE 0 00 V Figure 2 5 shows the same with PLL RPC EN bit in TRX RPC register enabled The device goes to power save mode during the PLL calibration period Figure 2 5 State Change from TRX OFF to RX ON with PES Mode Only Enabled Zoom Factor 40kX Zoom Position 31 75 a AVDD regulator PES Mode ramping and PLL power saving TRX_OFF state Calibration enabled RX_ON state PES mode power saving gt SE 4 b value Mean Min Max Std Dev 100s 500kS s 3 0 00 V In ASF MAC SDK the state change from TRX OFF to RX ON using the API set trx state will first set the transceiver to PLL ON state and then to RX ON RX AACK ON state Smart Reduced Power Consumption Techniques APPLICATION NOTE Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote 082014 TRX_OFF state to TX_ARET_ON and show the comparison of power consumption when there is a state change from TRX_OFF state to TX_ARET_ON state without and with PES mode enabled The code snippet below shows the ASF AVR2025 TAL 5 component API is used for setting the2. a aa el el lel el r r SE ll 24 2 00mA Value Mean Min res Std Dev 2 Max 4 885mA 4 885m 4 885m 4 885m 0 000 C2 min 258 4uA 258 44 258 44 258 4u 0 000 Z 200us s00ks s FK XT Smart Reduced Power Consumption Techniques APPLICATION NOTE 5 Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote 082014 shows the same with PLL_RPC_EN bit in TRX_RPC register enabled On enabling PES mode the PLL_ON state current consumption reduces to 450A Figure 2 3 State Change from TRX_OFF to PLL_ON with PES Mode Only Enabled 31 81416 s 251 2MA 31 814945 336 6MA A780 0000p5 A85 31yNA 2 2 00mA Value Mean Min Max Std Dev i 2 Max 4 802mA 4 802m 4 802m 4 802m 0 000 e jan OP min 222 5MA 222 5m 222 54 222 54 0 000 4 400ps BIE f 0 00v TRX OFF state to RX ON RX AACK ON and show the comparison of power consumption when there is a state change from TRX OFF state to RX ON RX AACK ON state without and with PES mode enabled The code snippet below shows the ASF AVR2025 TAL 5 component API used for setting the PLL RPC EN bit in TRX RPC register and for changing the state of the transceiver Code Snippet fer re DCA e TRX Piy pal trx reg write K RPC 0x09 Enable PES mode in RPC 7 set trx state CMD RX ON shows the power consumption of the device when the device changes its state from TRX_OFF to RX_ON RX_AACK_ON state Smart Reduced Power Consumption Techniques APPLICATION NOTE
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4. ON state with ERD Enabled and RX PDT LEVEL 0x08 Current consumption reduces by 2mA Value Mean Min Std Dev 7 400us SIGE fr 0 00V Figure 2 15 shows the power consumption with ERD only enabled and RX PDT LEVEL set to OxOF Here when the device is on RX ON RX AACK ON state the ERD mode reduces power consumption 8 5mA Figure 2 15 RX ON Mode with ERD Enabled and RX PDT LEVEL 0x0F Zoom Factor 10kX Zoom Position 30 55 a TRX_OFF state PLL Calibration RX ON state with ERD Enabled and RX PDT LEVEL 0x0F Current consumption reduces by 2 5mA Mean Min Std Dev Smart Reduced Power Consumption Techniques APPLICATION NOTE 15 Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote 082014 2 4 2 4 1 16 shows the power consumption with ERD disabled and RX_PDT_LEVEL set to OxOF Without ERD enabled RX_PDT_LEVEL bits set to greater than zero will reduce the current consumption by 0 5mA Here when the device is on RX_ON RX_AACK_ON state and reducing the receiver sensitivity reduces the power consumption by 0 5mA Figure 2 16 RX ON Mode with ERD Disabled and RX PDT LEVEL 0x0F 30 84238 5 10 31mA 30 84438 5 10 32mA A2 000000ms A10 16yA 5 00m i Value Mean Min Max Std Dev i 2 Max 10 65m 10 65m 10 65m 10 65m 0 000 2 Min 26 564A 26 56u 26 56 26 56 0 000 Z 4005 EE KI TPH Automated TX Power Handling Automated Tx Power handling mode helps t
5. PLL_RPC_EN bit in TRX_RPC register and for changing the state of the transceiver Code Snippet Set CYX Stete F pal trs reg EN RX UxC9 Enable PES mode in RPC sec CEK DCA e 2 shows the power consumption of the device when the device changes its state from TRX_OFF to TX_ARET_ON state Figure 2 6 State Change from TRX_OFF to TX_ARET_ON with RPC Disabled 31 677340 5 32 81MA 31 677740 5 4 527m 400 0000045 A4 494mA 2 5 00mA i Value Mean Min Max Std Dev 2 BET 4 593mA 4 593m 4 593m 4 593m 0 000 E min 10 16MA 10 16 10 16 10 16 0 000 ALUE 500ks s EG I 0 00 Vv shows the same with PLL RPC EN bit in TRX_RPC register enabled Smart Reduced Power Consumption Techniques APPLICATION NOTE Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote 082014 2 2 2 2 1 Figure 2 7 State Change from TRX_OFF to TX_ARET_ON with PES Mode Only Enabled 30 730530 s 39 06MA 30 730930 s 110 9MA A400 00000ys A71 88uA 2 5 00mA Value Mean Min Max Std Dev j 2 BUEN 4 538mA 4 538m 4 538m 4 538m 0 000 2 Woi 28 91uUA 28 91 28 91 28 91 0 000 Z 100s 500KS s 3 JE 0 00 V SRT Smart Receiving Technology Smart receiving technology when enabled reduces power consumption by periodically enabling and disabling the transceiver while listening for incoming frame Depending on the channel noise traffic environmental conditions the SRT mode helps in saving up to 50 of the current consump
6. Ser VP value NN pal trx reg write RPC 0xE3 enable SRT and PAM modes set Tex stalel 7 E shows the current consumption of the device with PAM disabled the device stays in receive mode during the frame reception period Figure 2 20 PAM Mode Disabled SRT Enabled Frame Reception with Same PAN and Different Destination Address CED A 125kS s f 1 24V 5M points Smart Reduced Power Consumption Techniques APPLICATION NOTE 19 Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote 082014 shows the current consumption with PAM enabled the device automatically enter the power save mode for the remaining frame and ACK period if the PAN Address matches and destination address does not matches Figure 2 21 PAM Mode Enabled SRT Enabled Frame Reception with Same PAN and Different Destination Address CET ar 125kS s f 1 24v 5M points and shows the power consumption comparison of the PAM mode during frame reception with different PAN address shows the current consumption of the device with PAM disabled the device stays in receive mode during the frame reception period 20 Smart Reduced Power Consumption Techniques APPLICATION NOTE Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote 082014 Figure 2 22 PAM Mode Disabled SRT Enabled Frame Reception with Different PAN Address Zoom Factor 4kX Zoom Position 34 05 RX_AACK_ON state with SRT enabled Incoming Fra
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8. during RX_ON RX_AACK_ON state Figure 2 8 RX_ON AACK_ON Mode with RPC Disabled Zoom Factor 10kX Zoom Position 29 25 Oo 6 TRX_OFF state PLL Calibration RX_ON RX AACK_ON state Value Mean Min Max Std Dev i 2 E 500KS s 3 JE 0 00 V Figure 2 9 shows the power consumption of the same with SRT enabled Here when the device is on RX ON RX AACK ON state the SRT mode reduces power consumption up to 50 by periodically enabling and disabling the transceiver while listening for incoming frames Figure 2 9 RX ON RX AACK ON Mode with SRT Mode Only Enabled Zoom Factor 10kKX Zoom Position 29 55 TRX_OFF state PLL Calibration RX ON RX AACK ON state SRT mode power saving value Mean Min Max Std Dev i Smart Reduced Power Consumption Techniques APPLICATION NOTE Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote 082014 and shows the minimum and maximum power saving behavior of the transceiver when SRT is enabled As mentioned above the power saving in SRT mode is dependent on channel noise traffic environmental conditions etc shows the minimum power saving behavior of SRT and the code snippet below shows the ASF AVR2025 TAL 5 component API for enabling SRT with minimum power saving by setting the register bits RX_RPC_EN bit and RX_RPC_CTRL bits Code Snippet Enabling SRT Mode with Minimum Power Saving Sel frk Slave Cub TR EE pal crx
9. req write tp RX RPC 0x21 Enable SRT mode with min power saving in RPC sel CrX SLA 13 Figure 2 10 SRT Enabled with Minimum Power Saving Activated i Ere 5 00m 4 2 2 00ms S00KS Ss 3 JE 0 00 V 20M points shows the maximum power saving behavior of SRT and the code snippet below shows the ASF AVR2025 TAL 5 component API for enabling SRT with maximum power saving Code Snippet Enabling SRT Mode with Maximum Power Saving Set TEx Stare A C v pal 160 VL RX I OXE1 Enable SRT mode with max power saving in RPC Ser trx stare X AACK I Smart Reduced Power Consumption Techniques APPLICATION NOTE 11 Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote 082014 Figure 2 11 SRT Enabled with Maximum Power Saving Activated Zoom Factor 2kX Zoom Position 29 55 RX ON RX AACK ON state RX ON RX AAGK ON state ___ CO Enabled with Maximum power saving CB SOMA 2 Ooms S00KS s 20M points Figure 2 12 shows the current consumption scope plot when the transceiver is receiving an incoming frame and sending the acknowledgement in RX_AACK_ON mode Figure 2 12 Frame Reception and Automatic ACK Transmission in RX_AACK_ON Mode with SRT Enabled Zoom Factor SkX doom Position 30 1s RX_AACK_ON state i RX AACK ON st te with SRT enabled 0o Incoming Frame Reception o BD ft gt with SRT enabled SRT mode power saving Sooman f
10. APPLICATION NOTE AT02594 Smart Reduced Power Consumption Techniques Atmel MCU Wireless Features e Supported in Atmel AT86RF233 ATmega2564 1284 644RFR2 and ATmega256 128 64RFR2 devices e PES PLL Energy Saving e SRT Smart Receiving Technology e ERD Extended Receiving Desensitizing e TPH Automated TX Power Handling e PAM PAN Address Match Recognition e Miscellaneous Power Reduction Functions Dynamic Frame Buffer Protection period power save Random back off period power save TX_ARET and RX AACK wait time Description Reduced Power Consumption RPC is a set of self contained self calibrating and adaptive power reduction scheme available in Atmel transceivers which helps in reducing the device power consumption further below the normal power consumption This application note describes about the various RPC modes available in megaRFR2 1 and AT86RF233 2 devices The document also provides a detailed profile showcasing the power consumption application scenarios to use RPC mode and benefits of RPC feature available in Atmel transceivers Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote 082014 Table of Contents T MOUNT 3 1 1 Measurement Setup rrrnnnnannanrnrannnrnnnrnnanrnrannrnranrnnannennnennansnnansnnannennunennassnnansennnsennnnennansnnnnennnsennanennn 3 2 RLE MOUSE 4 2 1 PES PLL Energy Saving Mode rrrnnnrrnrnnnrnnnnnnrnvnnnrnnrnnnrnnnnnnrnrnnnrn
11. EEE 802 15 4 2006 which performs random back off period During this period the transceiver automatically enters into power save mode 2 6 2 1 Current Profile shows the power save mode during random back off period when frame transmission is initiated from TRX_OFF state Figure 2 26 Power Save in Random Back Off Period 757 4400ms 1 836mA 758 5000ms 5 302m 4 A1 060000ms A3 466mA f VI il IA il IN I i 2 Beers shows the power save mode during random back off period when frame transmission is initiated from RX_ON RX_AACK_ON state Figure 2 27 Power Save in Random Back Off Period 6 985780 s 5 003mA 6 986470 s 6 398m A A690 0000pMs A1 395maA tl VW l Hl l NN MN I i Sa nt ti il i ll il i i ti i Ni 2 5 00mA4 Z 1 00ms 500KS Ss J 28 0m 24 Smart Reduced Power Consumption Techniques APPLICATION NOTE Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote 082014 2 6 3 2 6 3 1 3 TX_ARET and RX_AACK Wait Time As per IEEE 802 15 4 2006 transceiver should wait for a minimum turnaround time 12 symbol period when changing from Tx to Rx or Rx to Tx The Atmel transceivers will automatically transmit acknowledgement frame in TX_ARET_ON and RX_AACK_ON mode after 12 symbols period 192uSec for 2 4GHz of the reception of last symbol of data command frame During this wait time the transceiver automatically enters to power save mode Current Profile shows the p
12. RD enabled the current consumption reduces by 0 5mA for RX PDT LEVEL values from 0x01 to 0x07 2mA for RX PDT LEVEL equal to 0x08 and 2 5mA for RX PDT LEVEL from 0x09 to OxOF Table 2 1 Receiver Desensitization vs Power Consumption Receiver Desensitization Threshold Level Current consump Current consump in dBm tion with ERD disa tion with ERD ena RX PDT LEVEL bled bled Register Value AT86RF233 megaRFR2 Note The above characterization is taken with ERD enabled and SRT disabled By enabling the SRT mode the current consumption can be further reduced up to 50 i e wnen RX_PDT_LEVEL set to 0x08 with SRT and ERD enabled the average current consumption will reduce up to 4 5mA typically 5 1mA to 6 1mA Atmel Smart Reduced Power Consumption Techniques APPLICATION NOTE 13 Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote_082014 2 3 2 14 In AT86RF233 2 ERD mode enabled with RX PDT LEVEL set to 0x08 will reduce the power consumption in receive mode to 9mA for receiver sensitivity of 80dBm The current consumption can be further reduced by enabling the SRT mode With RX_PDT_LEVEL gt 8 ERD and SRT enabled will reduce the effective power consumption to 5 1mA in receive mode This configuration will reduce power consumption significantly in FFD s which has Receiver On When Idle mode enabled Note In this configuration the receiver sensitivity reduces to 79dBm During CCA and ED scan the ERD wil
13. Receiving Extended re Disable PLL Automated TX PAN Address always set to behavior in Smart mode ceiver desensi Energy saving Power handling match recognition 1 Receiving mode tizing Applicable States RX ON state RX ON state RX AACK ON PLL ON state RX AACK ON state and state and and TX ARET mode when waiting for an TX ARET mode TX ARET ON ACK when waiting for state an ACK RX_AACK_ON state RX_AACK_ON state The maximum power saving in RPC can be enabled by setting OxFF to TRX_RPC register The RPC features can be disabled by setting TRX_RPC register to OxC1 or 0x01 The reduced power saving in miscellaneous mode is enabled by default and it is not possible disable the power saving in these modes The code snippet below shows the ASF AVR 2025 TAL 5 component API used for enabling the maximum power saving in RPC Though the code snippet is provided for Atmel IEEE 802 15 4 MAC SDK it is possible to implement in similar way in other stacks as well Code Snippet set crx Stace CMD TRA GFE Pal trx reg Write R TRX RPC Ux r Enable all RPC features Smart Reduced Power Consumption Techniques APPLICATION NOTE Atmel Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote_082014 2 1 PES PLL Energy Saving Mode PLL energy saving mode helps to reduce the current consumption of the device by automatically entering into power save mode immediately after the PLL calibration A stat
14. ad Smart Reduced Power Consumption Techniques APPLICATION NOTE Atmel Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote_082014 Figure 2 24 RPC On with Frame Buffer Read After a Delay in AT86RF233 Zoom Factor Akk doom Position 8 02s 00 l e i gt al i l a i Frame RX_AACK_ON state with Incoming Frame Delay inserted in the stack Buffer fead SRT enabled gt gt gt Receptiot gt gt gt gt before frame bufferis read tal RX_AACK_ON state with SRT enabled Figure 2 25 shows the power consumption of megaRFR2 1 devices Here these devices does not support power save feature in during dynamic frame buffer protection period and the device does not go to power save mode until the frame buffer is read Figure 2 25 RPC On with Frame Buffer Read After a Delay in ATmega256RFR2 Zoom Factor 500 X Zoom Position 8 69 3 Incoming Frame H Franie Buffer RX_AACK ON state Reception and Delay inserted in the stack read with SRT enabled gt ACKTx gt gt before frame bufferisread gt gt 4 RX_AACK_ON state with SRT enabled Smart Reduced Power Consumption Techniques APPLICATION NOTE 23 Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote 082014 2 6 2 Random Back Off Period Power Save In TX_ARET Transmit with automatic frame retransmission and CSMA CA retry mode the transceiver will perform CSMA CA algorithm as defined by I
15. e 800ms i Masks MV amp M I 39 90ma B Amplitude 8 200mA 5M points 12 Smart Reduced Power Consumption Techniques APPLICATION NOTE Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote 082014 2 3 ERD Extended Receiving Desensitizing AT86RF233 2 transceivers and megaRFR2 1 SoC s have an outstanding sensitivity performance of 101dBm For certain Applications Environmental condition or for High Data Rate modes it may be useful to decrease the receiver sensitivity This can be achieved by adjusting the receiver sensitivity threshold using register bits RX PDT LEVEL in RX SYN Register 0x15 The Extended Receiver Desensitizing mode ERD in RPC helps in reducing the power consumption of the device when receiver sensitivity reduced by configuring RX PDT LEVEL bits The ERD can be enabled by setting the PDT RPC EN bit in TRX RPC register and is applicable to RX ON RX AACK ON and TX ARET states Table 2 1 shows the RX PDT LEVEL register value and the receiver desensitization threshold value dBm The receiver sensitivity threshold value is calculated by the equation e RX THRES gt RSSI BASE VAL 3 RX PDT LEVEL 1 for RX PDT LEVEL gt Setting RX PDT LEVEL x 8 requires special attention In contrast to the above equation RX PDT LEVEL 0x08 will reduce the sensitivity to 80dBm Without ERD enabled RX PDT LEVEL bits set to greater than zero will reduce the current consumption by 500uA With E
16. e change towards PLL_ON TX_ARET_ON RX_ON RX_AACK_ON and channel switch causes a PLL wake up and starts PLL calibration run After finishing such PLL calibration the PLL automatically enters to power save mode if PES mode is enabled The PES mode can be enabled by setting the PLL RPC EN bit in TRX_RPC register and is applicable to PLL ON and TRX_ARET_ON state With PES mode enabled the power consumed in PLL ON state reduces from 5 2mA typically to 450mA After the initial PLL run within the selected channel the PLL will be disabled on PLL locked channel The PES mode when enabled save power by automatically entering into power save mode Current Profile and shows the comparison of power consumption when there is a state change from TRX_OFF state to PLL_ON state without and with PES mode enabled The code snippet below shows the ASF AVR2025 TAL 5 component API used for setting the PLL_RPC_EN bit in TRX_RPC register and for changing the state of the transceiver Code Snippet Sel Tre Slave F pal trx reg write Rt BPC US 7 Dnable PES mode in RPC 7 eet CIZ State j ON TRX OFF to PLL ON state shows the power consumption of the device when the device changes its state from TRX OFF to PLL ON state Here the device is consuming 5mA 4 83mA Oscilloscope Offset 200uA in PLL ON state Figure 2 2 State Change from TRX OFF to PLL ON with RPC Disabled 31 820560 287 5MA 31 8212845 4 831mA Af24 00000US A4 544mA
17. he ACK frame is transmitted at full power here the nodes are kept far away Figure 2 19 TPH Mode Enabled SRT Enabled with Nodes kept Far Away Zoom Factor 10kX Zoom Position 48 45 RX_AACK_ON state Incoming Frame with SRT enabled Reception ACK TX RX_AACK_ON state with SRT enabled lt g ACK Tx output power is automatically increased Value Mean Min Max Std Dev Z 1 00ms 100kS Ss 18 Smart Reduced Power Consumption Techniques APPLICATION NOTE Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote 082014 2 5 2 5 1 PAM PAN Address Match Recognition PAN Address Match Recognition mode PAM when enabled reduces power consumption by automatically entering the power save mode for the remaining frame and ACK period if the PAN Address matches and destination address does not matches If PAN address does not match a new listen period starts immediately This feature is helpful in big network with lots of nodes Current Profile and show the power consumption comparison of the PAM mode during frame reception with same PAN and different destination The code snippet below shows the ASF AVR2025 TAL 5 component API used for setting the device short address pan id and enabling PAM and SRT mode Code Snippet Enabling PAM Mode ser TrZ Stare FF Set short address temp tal pib Set Mm A i Pibo valne t NNN Set PAN ID temp PAN ID cal pib
18. l be disabled automatically Current Profile and shows the comparison of power consumption in RX_ON RX_AACK_ON mode without and with ERD enabled The code snippet below shows the ASF AVR2025 TAL 5 component API used for enabling ERD mode and setting RX PDT LEVEL to 0x08 Code Snippet Enabling ERD Mode and Setting RX PDT LEVEL to 0x08 Set Crx Stave Q 2 pal trx reg write JA enable ERD tal Sel rz sensitivity level Uxu8 RX PDT LEVEL set to Ox08 Set ULA Stare L shows the power consumption of the device in RX ON RX AACK ON mode with ERD disabled and RX PDT LEVEL set to 0x00 Here the device consumes 11mA of current during RX ON RX AACK ON state Figure 2 13 RX ON Mode with ERD Disabled and RX PDT LEVEL 0x00 29 22556 5 10 76mA 29 22756 5 10 79m A2 000000ms PEPE 5 00m value Mean Min Max Std Dev 2 Max 10 81mA 10 81m 10 81m 10 81m 0 000 fo min 36 72MA 36 724 36 724 36 724 0 000 2400ps sooks s EL FEKK shows the power consumption of the same with ERD only enabled and RX PDT LEVEL set to 0x08 Here when the device is on RX ON RX AACK ON state the ERD mode reduces power consumption 9mA Smart Reduced Power Consumption Techniques APPLICATION NOTE Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote 082014 Figure 2 14 RX ON Mode with ERD Enabled and RX PDT LEVEL 0x08 zoom Factor 10kX Zoom Position 29 95 bl TRX OFF state PLL Calibration RX
19. me Reception RX AACK ON state with SRT enabled AN ANAN p T Gp 5 00mAQ 2 1 00ms 125kS s Ja 1 24 V 5M points Figure 2 23 shows the current consumption with PAM enabled here the PAN address does not matches and a new listen period has started immediately In this case the device is not blocked to receive undesirable frame and is now ready to receive frames from the own network Figure 2 23 PAM Mode Enabled SRT Enabled Frame Reception with Different PAN Address Zoom Factor 4kxX Zoom Position 33 95 RX_AACK_ON state with SRT enabled Incoming Frame Reception RX_AACK_ON state with SRT enabled i ni ill i il LL Hl E1 5 00mAQ Iz Feen 00ms 125kS s 1 24 V 5M points Smart Reduced Power Consumption Techniques APPLICATION NOTE 21 Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote 082014 2 6 2 6 1 2 6 1 1 22 Miscellaneous Power Reduction Functions In addition to the power saving techniques mentioned in Section 2 1 to 2 5 AT86RF233 and megaRFR2 devices can reduce power consumption further in following periods a Dynamic Frame Buffer protection period power save is only in AT86RF233 b Random back off period c TX ARET and RX AACK wait period The power save in these modes will get enabled automatically when these features are enabled and it is not possible to disable the feature alone with feature enabled Dynamic Frame Buffer Pr
20. nNote 082014 Code Snippet Enabling TPH Mode set Trx State 3 Set short address temp tal pib Ser im pib value Jie Set PAN ID temp Lal pib seli y pib value t tenp pal trx reg write lt RPC OxE5 enable SRT and TPH modes set trr state ie shows the current consumption of the device with TPH disabled where both transmitting and receiving nodes are kept nearby Figure 2 17 TPH Mode Disabled SRT Enabled with Nodes kept Nearby i J il Ul nm A Mm tH NA MI I Ul it i INi N VI ill m ETT i MM LL INA N HH i AVL HANN hh i i Mh I iil NA HIN Ul Hl I VM Ul it VEN Il PT LI ULL Alt NN HI i Y 2 BERU Value Mean Min Max Std Dev 12 04mA 12 04m 12 04m 12 04m 0 000 251 6MA 251 6 251 64 251 64 0 000 Z 1 00ms ee f 28 0mA shows that device automatically reduces the power of ACK frame here the nodes are kept nearby Smart Reduced Power Consumption Techniques APPLICATION NOTE 17 Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote 082014 Figure 2 18 TPH Mode Enabled SRT Enabled with Nodes kept Nearby Zoom Factor 10kX Zoom Position 46 5 RX AACK ON state Incoming Frame with SRT enabled Reception ACK TX RX_AACK_ON state with SRT enabled ACK Tx output power is automatically reduced Value Mean Min Max Std Dev Z 1 00ms 100kS s 1 28 0mA Figure 2 19 shows that t
21. nrennennvanernnennernrunennnennnnnranenneenneenn 25 DN EPER 25 3 RANE cect cree eon Gatco ere eaten es os erate deaa eeddeenawrenaeieuncineties nec nnmnnn 25 FREVISIOIN FI SCOR EEE EEEE A EE E E aE EAEE ENEE 26 Smart Reduced Power Consumption Techniques APPLICATION NOTE Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote_082014 Atmel 1 Introduction RPC is an extended feature available in AT86RF233 2 transceivers and megaRFR2 1 which help to reduce power consumption further below the normal power consumed by typical IEEE 802 15 4 transceivers The RPC feature along with extended operating modes makes AT86RF233 2 and megaRFR2 1 devices an ideal choice for IEEE802 15 4 based wireless products RPC offers a variety of independent techniques and methods to significantly reduce the power consumption over various scenarios Table 1 1 shows the various RPC modes available in AT86RF233 2 transceivers and megaRFR2 1 SoC s Table 1 1 Reduced Power Consumption RPC Modes RPC mode AT86RF233 megaRFR2 Basr srono remes vr v 20800 semsonsamommmmg 7 v Er a G asom emnene 20 orane Fame Buter preson oroare 2oznneenorrowsrowrsee ooanermmmennan v v The focus of this application note is to detail the RPC modes available their usage and implementation This document also provides power profile for usage scenarios with and without RPC to showcase the achievable power con
22. nrnnnrnnnnnnrnnnnnsnnnnsnsnnnnnsrnsnnsnnnnsensnnne 5 At CUNEN FOG neie E EE Ei 5 2 2 SRT Smart Receiving Technology ccceccccseeeeeeeeeeeeceeeeeeseeeeeeeeeeeseeeeeeseeeeesseeeeeseeeeeesaeeeesseeeeesaeees 9 PeT GE 3 18 ae 0 EE E 9 2 3 ERD Extended Receiving DeSeNsitiZing cccccsseccssececsececeuceseseecesececseeeseueessueesesesenseeensueessaeees 13 Craik OG 9 FLOM EEE NN 14 2 4 TPH Automated TX Power Handling rrnrrnnnnnnnnnnnrnnnnnnnnrnnnnrnrnnnnrnnrennnnrnnnnrnnnnsnnnnrennnnennnnennnnsnnnsennnsee 16 2 4 1 Current Profile rrrarnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnennnnnnnnnnnnnnnnnnnnnnnnnnnnennnnnnnnnnnnunnnnnnnuenne 16 2 5 PAM PAN Address Match Recognition rrnrrrrnrrvrnnrevnnrennnrrnrnrrnrnnrernnrernnrernnnrnnnnrennnnennnsennnennnsnennnnee 19 2 5 1 Current Profile rarrrrnnnnnrarernnnnnnrnnernrnnnrrunereenneerunernenneerunernennenruneruennneruneruennnerunenuennneruneruennsenn 19 2 6 Miscellaneous Power Reduction Functions rrrarrnrrvarerarnnreranerannnerrnnerannnnennnerannneenunenannneenusenunneenen 22 2 6 1 Dynamic Frame Buffer Protection Period Power Save ccccseccccseeeeeeeeeeeeeeeeeeeseeeeesaeeeeesaes 22 PNE 22 2 6 2 Random Back Off Period Power Save r rrrvrrrrurerurvnvrrrereenneernrereenneernrernenneerunernennnerusernennsennr 24 PAGE Curent OU EE EE EE EE 24 2 6 3 TX ARET and RX AACK Wait Time rorerarernrrrnnrerarennrrnnarer
23. o reduce the current consumption of device by automatically adapting the transmission power according to the combination of received frame ED and LQI values This feature is present only in AT86RF233 2 and not available in megaRFR2 1 devices When a frame is received successfully with ED gt 77dBm and LQI gt 224 the Tx output power is automatically adeptly reduced The minimum transmit power is 17dBm ED gt 45dBm and LQI gt 224 whereas the maximum transmit power will be the value which was configured in TX PUR register If the first frame transmission fails with the reduced Tx output power as set by the TPH the next frame retry starts with the maximum Tx output power Current Profile and show the power consumption comparison of the Tx power handling mode disabled enabled with nodes kept nearby and far away Here the device is configured to transmit at maximum power shows that the device is transmitting the acknowledgement at maximum power when TPH is disabled whereas shows that device automatically reduces the power of ACK frame since the nodes are kept nearby and shows that the ACK frame is transmitted at full power since the nodes are kept far away The code snippet below shows the ASF AVR2025 TAL 5 component API used for setting the device short address pan id and enabling TPH mode Smart Reduced Power Consumption Techniques APPLICATION NOTE Atmel 42356A Smart Reduced Power Consumption Techniques Applicatio
24. otection Period Power Save Dynamic frame buffer when enabled prevents a newly received valid frame passes to frame buffer until a frame buffer read has ended This feature when enabled helps to relax timing requirement for a frame buffer read access In AT86RF233 2 when dynamic frame buffer protection enabled the device automatically enters in power save mode until the frame buffer is read The power save feature is not present in megaRFR2 1 devices and the device will not enter power save mode The code snippet below shows the ASF AVR2025 TAL 5 component API used for enabling Dynamic Frame protection and enabling all the RPC modes Code Snippet Enabling PAM Mode Set trz Stace CMD TRA OFF pal trx bit write SR RX SAFE MODE RX SAFE MODE ENABLE Enable buffer protection mode pal trx reg write RG TRX RPC OxFF RPC feature configuration set trx state CMD RX AACK ON Note Itis recommended to disable enable dynamic frame buffer protection in TRX OFF state and then switch to RX_ON RX_AACK_ON state to re activate SRT Current Profile To understand the current consumption in this mode a long delay is inserted in ASF AVR2025 TAL 5 component API component before the frame buffer is read Figure 2 24 shows the power consumption in AT86RF233 2 device Here the device enters into a long delay routine before the frame is read and the device automatically switches to power save mode until the frame buffer is re
25. ower saving during the turnaround time after reception of a frame to sending of acknowledge frame As per IEEE 802 15 4 2006 specification the turnaround time is 12 symbols period and shows that the device enters in power save mode during the automatic acknowledge transmission in RX_AACK_ON mode Figure 2 28 Power Save in RX AACK Waits Period 6 990078 s 7 410mA 6 990270 5 3 142m A 192 000045 A4 268mA MAAN ANE l FRP TL me yy TE i NANA VM V YNA 5 00m Reference 1 2 3 4 9 Smart Reduced Power Consumption Techniques APPLICATION NOTE 25 Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote 082014 4 Revision History Doc Rev Date Comments 42356A 08 2014 Initial document release 26 Smart Reduced Power Consumption Techniques APPLICATION NOTE Atmel Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote_082014 Altmel Enabling Unlimited Possibilities vin W Atmel Corporation 1600 Technology Drive San Jose CA 95110 USA T 1 408 441 0311 F 1 408 436 4200 www atmel com 2014 Atmel Corporation Rev Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote_082014 Atmel Atmel logo and combinations thereof AVR Enabling Unlimited Possibilities and others are registered trademarks or trademarks of Atmel Corporation in U S
26. sumption reduction with individual modes 1 1 Measurement Setup e Hardware REB233SMAD EK kit 3 ATmega256RFR2 Xplained Pro 4 e Test setup Tektronix MSO 4054 Mixed signal oscilloscope 5S00MHz 2 5GS s With 100 1 metal film resistor as shunt resistor e REB233SMAD EK 3 Across JP1 in REB233SMAD transceiver board e ATmega256RFR2 XPRO 4 Across J101 VCC_ Target and VCC_MCU External power supply is connected to VIG and GND pins in REB233SMAD EK kit 3 J100 VCC_P3V3 and GND pins in ATmega256RFR2 Xplained Pro board 4 Atmel Smart Reduced Power Consumption Techniques APPLICATION NOTE 3 Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote_082014 Figure 1 2 Oscilloscope Setup Oscilloscope ATmega 56RFR2 3 0V Resistor 10 Ohm 1 AT8GRE233 Power Supply Oscilloscope measurements are expected to have offset of around 0 2mA This error was calculated by measuring a constant current using both multimeter and oscilloscope Note All measurement results are typical values RPC Modes The different mode of the RPC can be enabled or disabled by configuring the register TRX_RPC Figure 2 1 shows the TRX_RPC register configuration Figure 2 1 TRX_RPC Register T 6 5 4 3 2 1 0 RX_RPC_CTRL RX_RPC_EN PDT RPC EN PLL RPC EN XAH TX RPC EN IPAN RPC EN Activate max min Enable Disable Enable Disable Enable Enable Disable Enable Disable Should be power saving Smart
27. tion in RX_ON and RX_AACK_ON modes The SRT mode is enabled by setting the RX_RPC_EN bit in TRX_RPC register When SRT is enabled the SRT is also active in TX_ARET mode when waiting for a requested acknowledgment Setting the RX_RPC_CTRL bits activates the maximum power saving behavior of the SRT mode In this mode 1dB sensitivity loss is expected The application must disable the SRT mode when performing the following actions RSSI Measurement Random Number Generation During CCA and ED Scan the transceiver automatically disables the SRT mode If antenna diversity is enabled the SRT mode cannot achieve the power saving in receiving mode as expected SRT mode helps in reducing power consumption of the devices significantly which has Receiver On When Idle mode enabled Current Profile and shows the comparison of power consumption in RX_ON RX_AACK_ON mode without and with SRT enabled The code snippet below shows the ASF AVR2025 TAL 5 component API used for setting the RX_RPC_EN and RX_RPC_CTRL bits and to set RX_AACK_ON state Code Snippet eet Tre ST FF pal trx reg rrite RX UxXEl Enable SRT mode in APC SeT DEX Stele X AAC N Smart Reduced Power Consumption Techniques APPLICATION NOTE 9 Atmel 42356A Smart Reduced Power Consumption Techniques ApplicationNote 082014 10 Figure 2 8 shows the power consumption of the device in RX_ON RX_AACK_ON mode with SRT disabled Here the device consumes 11mA of current
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