Semtech LR1121 - VBAT Measurement; Getvbat; Table 5-3: Getvbat Command; Table 5-4: Getvbat Response

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LR1121

User Manual Rev 1.1

UM.LR1121.W.APP Mar 2023

42 of 130

Semtech

Proprietary & Confidential

www.semtech.com

5.2 VBAT Measurement

5.2.1 GetVbat

GetVbat(...) command monitors the battery supply voltage, it returns the Vbat voltage as a function of a reference

voltage:

Table 5-3: GetVbat Command

Byte 0 1

Data from Host 0x01 0x19

Data to Host Stat1 Stat2

Table 5-4: GetVbat Response

Byte 0 1

Data from Host 0x00 0x00

Data to Host Stat1 Vbat(7:0)

VBAT V 

5 VBat(7:0)

255

----------------------------------

 

 

1–

 

 

1.35=

Main Page

Table of Contents3
Introduction12
Scope12
Overview12
Figure 1-1: LR1121 Block Diagram12
System Processes13
System Modes13
Figure 2-1: LR1121 Modes and Transitions13
Boot14
Standby14
Figure 2-2: Bootloader14
Table 2-1: Setstandby Command14
Calibrations15
Table 2-2: Calibimage Command15
Table 2-3: ISM Band Values15
Power down16
Table 2-4: Calibrate Command16
Table 2-5: Calibparams Parameter16
Sleep17
Table 2-6: Setsleep Command17
Table 2-7: Sleepconfig Parameter17
Table 2-8: Sleep Mode Summary17
Reset18
Table 2-9: Reboot Command18
RX Mode19
TX Mode19
FS Mode20
Startup Sequence20
Table 2-10: Setfscommand20
Firmware Upgrade21
Getversion21
Eraseflash21
Table 2-11: Getversion Command21
Table 2-12: Getversion Response21
Table 2-13: Eraseflash Command21
Writeflashencrypted22
Mode Transitions & Timings22
Table 2-14: Writeflashencrypted Command22
Table 2-15: Mode Transitions and Timings22
Info Page23
Eraseinfopage23
Writeinfopage23
Table 2-16: Eraseinfopage Command23
Table 2-17: Writeinfopage Command23
Readinfopage24
Table 2-18: Readinfopage Command24
Table 2-19: Readinfopage Response24
Host-Controller Interface25
Write Commands25
Read Commands25
Figure 3-1: Write Command Timing Diagram25
Figure 3-2: Read Command Timing Diagram25
Command Endianness26
Figure 3-3: Getversion Write Capture26
Figure 3-4: Getversion Read Capture26
Status Registers27
Getstatus27
Stat127
Table 3-1: Getstatus Command27
Table 3-2: Stat1 Values27
Stat228
Table 3-3: Stat2 Values28
Busy29
Figure 3-5: BUSY Timing Diagram29
Errors30
Geterrors30
Clearerrors30
Table 3-4: Geterrors Command30
Table 3-5: Geterrors Response30
Table 3-6: Clearerrors Command30
Memory Access31
Writeregmem3231
Readregmem3231
Table 3-7: Writeregmem32 Command31
Table 3-8: Readregmem32 Command31
Table 3-9: Readregmem32 Response31
Writeregmemmask3232
Writebuffer832
Table 3-10: Writeregmemmask32 Command32
Table 3-11: Writebuffer8 Command32
Readbuffer833
Clearrxbuffer33
Getrandomnumber33
Table 3-12: Readbuffer8 Command33
Table 3-13: Readbuffer8 Response33
Table 3-14: Clearrxbuffer Command33
Table 3-15: Getrandomnumber Command33
Table 3-16: Getrandomnumber Response33
Enablespicrc34
Table 3-17: Enablespicrc Command34
Gpios35
Interrupts35
Table 4-1: Digital I/Os35
Table 4-2: Irqtoenable Interruption Mapping36
Setdioirqparams37
Clearirq37
Table 4-3: Setdioirqparams Command37
Table 4-4: Clearirq Command37
RF Switch Control38
Setdioasrfswitch38
Table 4-5: Setdioasrfswitch Command38
Drivediosinsleepmode39
Table 4-6: Drivediosinsleepmode Command39
Temperature Sensor40
Gettemp40
Table 4-7: Gettemp Command40
Table 4-8: Gettemp Response40
Power Distribution41
Power Modes41
Setregmode41
Table 5-1: Setregmode Command41
Table 5-2: Power Regulation Options41
VBAT Measurement42
Getvbat42
Table 5-3: Getvbat Command42
Table 5-4: Getvbat Response42
Power-On-Reset and Brown-Out-Reset43
Low Battery Detector43
Over Current Protection43
Figure 5-1: LR1121 por and BRN Functions43
Clock Sources44
RC Oscillators Clock References44
High-Precision Clock References44
Khz Crystal44
32Mhz Crystal44
32Mhz TCXO45
Figure 6-1: LR1121 Thermal Insulation on PCB Top Layer45
Figure 6-2: TCXO Circuit Diagram45
Commands46
Configlfclock46
Table 6-1: Configlfclock Command46
Settcxomode47
Table 6-2: Settcxomode Command47
Table 6-3: TCXO Supply Voltage Programming Values47
Radio48
Overview48
Figure 7-1: Radio48
Commands49
Setrffrequency49
Setrx49
Table 7-1: Setrffrequency Command49
Table 7-2: Setrx Command49
Settx50
Table 7-3: Settx Command50
Autotxrx51
Table 7-4: Autotxrx Command51
Setrxtxfallbackmode52
Table 7-5: Setrxtxfallbackmode Command52
Setrxdutycycle53
Table 7-6: Setrxdutycycle Command53
Figure 7-2: LR1121 Current Profile During RX Duty Cycle Operation54
Figure 7-3: RX Duty Cycle Upon Preamble Detection54
Stoptimeoutonpreamble55
Getrssiinst55
Table 7-7: Stoptimeoutonpreamble Command55
Table 7-8: Getrssiinst Command55
Table 7-9: Getrssiinst Response55
Getstats56
Resetstats56
Table 7-10: Getstats Command56
Table 7-11: Getstats Response56
Table 7-12: Resetstats Command56
Getrxbufferstatus57
Setrxboosted57
Table 7-13: Getrxbufferstatus Command57
Table 7-14: Getrxbufferstatus Response57
Table 7-15: Setrxboosted Command57
Setlorasyncword58
Getlorarxheaderinfos58
Table 7-16: Setlorasyncword Command58
Table 7-17: Getlorarxheaderinfos Command58
Table 7-18: Getlorarxheaderinfos Response58
Setrssicalibration59
Table 7-19: Setrssicalibration Command59
Table 7-20: Gain Tune Values59
Table 7-21: Recommended Values for Reference EVK59
Modems62
Modem Configuration62
Figure 8-1: Lora /(G)FSK / LR-FHSS Command Order62
Setpackettype63
Getpackettype63
Table 8-1: Setpackettype Command63
Table 8-2: Getpackettype Command63
Table 8-3: Getpackettype Response63
Lora® Modem64
Lora Modulation Principle64
Figure 8-2: Lora Signal Bandwidth64
Lora Packet Format65
Figure 8-3: Lora Packet Format65
Channel Activity Detection (CAD)66
Lora® Commands67
Setmodulationparams67
Table 8-4: Setmodulationparams Command67
Setpacketparams68
Setcad68
Table 8-5: Setpacketparams Command68
Table 8-6: Setcad Command68
Setcadparams69
Setlorasynchtimeout69
Table 8-7: Setcadparams Command69
Table 8-8: Cadexitmode Parameter69
Table 8-9: Setlorasynchtimeout Command69
Setlorapublicnetwork70
Getpacketstatus70
Table 8-10: Setlorapublicnetwork Command70
Table 8-11: Getpacketstatus Command70
Table 8-12: Getpacketstatus Response70
G)FSK Modem71
G)FSK Modulation Principle71
G)FSK Packet Engine71
G)FSK Packet Format72
Figure 8-4: Fixed-Length Packet72
Figure 8-5: Variable-Length Packet72
Sx128X Compatibility73
G)FSK Commands74
Setmodulationparams74
Table 8-13: Setmodulationparams Command74
Table 8-14: Bandwidth Parameter74
Setpacketparams75
Table 8-15: Setpacketparams Command75
Setgfsksyncword76
Setpacketadrs76
Table 8-16: Setgfsksyncword Command76
Table 8-17: Setpacketadrs Command76
Setgfskcrcparams77
Setgfskwhitparams77
Table 8-18: Setgfskcrcparams Command77
Table 8-19: Setgfskwhitparams Command77
Getpacketstatus78
Table 8-20: Getpacketstatus Command78
Table 8-21: Getpacketstatus Response78
LR-FHSS Modulation79
LR-FHSS Modulation Principle79
Figure 8-6: LR-FHSS Spectral Plot Example79
LR-FHSS Commands80
Setmodulationparams80
Lrfhssbuildframe80
Table 8-22: Setmodulationparams Command80
Table 8-23: Lrfhssbuildframe Command80
Table 8-24: Maximum User Payload Length, in Bytes81
Lrfhsssetsyncword82
Circuit Configuration for Long Range FHSS Transmission82
Table 8-25: Lrfhsssetsyncword Command82
Data Buffer83
RSSI Functionality83
Table 8-26: RSSI Information Origin and Meaning83
Power Amplifiers84
Figure 9-1: LR1121 Power Amplifiers84
PA Supply Scheme85
Figure 9-2: PA Block Diagram85
Low Power PA86
Figure 9-3: Low Power PA VR_PA Voltage Vs86
High Power PA87
Figure 9-4: High Power PA VR_PA Voltage Vs. Txpower87
PA Output Power88
Low Power PA88
Figure 9-5: Low Power PA Output Power Vs. Txpower88
High Power PA89
Figure 9-6: HP PA Output Power Vs. Txpower89
High Frequency PA90
Figure 9-7: High Frequency PA Output Power Vs. Txpower90
PA Current Consumption91
Low Power PA91
Figure 9-8: IDDTX Vs Txpower, Low Power PA, DC-DC Configuration91
High Power PA92
Figure 9-9: IDDTX Vs Txpower, Low Power PA, LDO Configuration92
Figure 9-10: IDDTX Vs Txpower, High Power PA, DC-DC Configuration93
Figure 9-11: IDDTX Vs Txpower, High Power PA, LDO Configuration93
High Frequency PA94
Figure 9-12: IDDTX Vs Txpower, High Frequency PA, DC-DC Configuration94
Figure 9-13: IDDTX Vs Txpower, High Frequency PA, LDO Configuration94
Impedance Matching Networks95
Multi-Band Operation95
Table 9-1: Optimized Settings for LP PA with the same Matching Network95
Table 9-2: Optimized Settings for HP PA with the same Matching Network95
Table 9-3: Optimized Settings for HF PA with the same Matching Network95
RF Switch Implementation97
Figure 9-14: RF Switch, Double PA Operation97
Figure 9-15: RF Switch, Single PA Operation (High Power PA Example)97
Direct-Tie Implementation98
Figure 9-16: Single Tie Implementation: Only One PA Used (High Power PA Example)98
Figure 9-17: Single Tie Implementation: both Pas Used (High Power PA Example)98
Commands99
Setpaconfig99
Table 9-4: Setpaconfig Command99
Table 9-5: Dutycycle Parameters99
Settxparams100
Table 9-6: Settxparams Command100
Table 9-7: Ramptime Values100
Cryptographic Engine101
Description101
Cryptographic Keys Definition101
Table 10-1: Cryptographic Keys Usage and Derivation101
Commands103
Cestatus103
Cryptosetkey103
Table 10-2: Cryptosetkey Command103
Table 10-3: Cryptosetkey Response103
Cryptoderivekey104
Table 10-4: Cryptoderivekey Command104
Table 10-5: Cryptoderivekey Response104
Cryptoprocessjoinaccept105
Table 10-6: Cryptoprocessjoinaccept Command105
Table 10-7: Cryptoprocessjoinaccept Response105
Cryptocomputeaescmac106
Table 10-8: Cryptocomputeaescmac Command106
Table 10-9: Cryptocomputeaescmac Response106
Table 10-10: Cryptocomputeaescmac Command Example106
Table 10-11: Cryptocomputeaescmac Response Example106
Cryptoverifyaescmac107
Table 10-12: Cryptoverifyaescmac Command107
Table 10-13: Cryptoverifyaescmac Response107
Cryptoaesencrypt01108
Table 10-14: Cryptoaesencrypt01 Command108
Table 10-15: Cryptoaesencrypt01 Response108
Cryptoaesencrypt109
Table 10-16: Cryptoaesencrypt Command109
Table 10-17: Cryptoaesencrypt Response109
Cryptoaesdecrypt110
Table 10-18: Cryptoaesdecrypt Command110
Table 10-19: Cryptoaesdecrypt Response110
Cryptostoretoflash111
Cryptorestorefromflash111
Table 10-20: Cryptostoretoflash Command111
Table 10-21: Cryptoaesdecrypt Response111
Table 10-22: Cryptorestorefromflash Command111
Table 10-23: Cryptorestorefromflash Response111
Cryptosetparam112
Cryptogetparam112
Table 10-24: Cryptosetparam Command112
Table 10-25: Cryptosetparam Response112
Table 10-26: Cryptogetparam Command112
Table 10-27: Cryptogetparam Response112
LR1121 Provisioning113
Description113
Provisioning Commands113
Getchipeui113
Table 11-1: Getchipeui Command113
Table 11-2: Getchipeui Response113
Getsemtechjoineui114
Table 11-3: Getsemtechjoineui Command114
Table 11-4: Getsemtechjoineui Response114
Deriverootkeysandgetpin115
Table 11-5: Deriverootkeysandgetpin Command (Standard)115
Table 11-6: Deriverootkeysandgetpin Response115
Table 11-7: Deriverootkeysandgetpin Command (Advanced)116
Table 11-8: Deriverootkeysandgetpin Response (Advanced)116
Crypto Engine Use with Lorawan V1.1.X117
Figure 11-1: Key Derivation Scheme for Lorawan 1.1.X117
Crypto Engine Use with Lorawan V1.0.X118
Figure 11-2: Key Derivation Scheme for Lorawan 1.0.X118
Table 11-9: Lorawan 1.0.X Vs. 1.1.X Security Correspondence Table118
Test Commands119
Regulatory Overview119
Etsi119
Fcc119
Table 12-1: ETSI Test Signals119
Commands120
Settxcw120
Settxinfinitepreamble120
Table 12-2: Settxcw Command120
Table 12-3: Settxinfinitepreamble Command120
List of Commands121
Register / Memory Access Operations121
Table 13-1: Register / Memory Access Operations121
System Configuration / Status Operations122
Table 13-2: System Configuration / Status Operations122
Radio Configuration / Status Operations123
Table 13-3: Radio Configuration / Status Operations123
Table 13-4: Cryptoelement Configuration / Status Operations125
Table 13-5: Bootloader Commands126
Table 14-1: Revision History127

Semtech LR1121 - VBAT Measurement; Getvbat; Table 5-3: Getvbat Command; Table 5-4: Getvbat Response

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