Revision 2.0 – July 2010
Page 17 of 24
www.semtech.com
© Semtech 2010
SX1231-31SKB
USER GUIDE
(which should not be confused with the LNA or AGC threshold) can be calculated from and equates to the
effective noise floor of the receiver for a given filter bandwidth.
dBm
]
DemodSNR
)
RxBw
*
2
log(
*
10
NF
174
[
RSSIthres
+
+
+
−
=
Figure 21: RSSI Window
5.4 Irq & Mapping Configuration Register Tab
The Irq & Mapping Configuration Register Tab is illustrated in Figure 22. Please refer to the SX1231 for a
full description of the irq and mappings for each mode of operation of the SX1231.
Configuration register value entries can be selected from the drop down menus besides each DIO listed.
Note that when necessary the GUI will automatically re-configure DIO mappings (i.e. Packet Handler
operation).
Please refer to Table 1 and Table 2, below, for the available DIO mappings of the SX1231 in continuous
and packet mode, respectively.
Mode
DIOx
Mapping
DIO5
DIO4
DIO3
DIO2
DIO1
DIO0
00
-
-
-
-
-
-
01
-
-
-
-
-
-
10
LowBat
LowBat
AutoMode
-
LowBat
LowBat
Sleep
11
ModeReady
-
-
-
-
ModeReady
00
ClkOut
-
-
-
-
-
01
-
-
-
-
-
-
10
LowBat
LowBat
AutoMode
-
-
LowBat
Standby
11
ModeReady
-
-
-
LowBat
ModeReady
00
ClkOut
-
-
-
-
PllLock
01
-
-
-
-
-
-
10
LowBat
LowBat
AutoMode
-
LowBat
LowBat
FS
11
ModeRady
PllLock
-
-
PllLock
ModeReady
00
ClkOut
Timeout
Rssi
Data
Dclk
SyncAddr
01
Rssi
RxReady
RxReady
Data
RxReady
Timeout
10
LowBat
SyncAddr
AutoMode
Data
LowBat
Rssi
RX
11
ModeReady
PllLock
Timeout
Data
SyncAddr
ModeReady
00
ClkOut
TxReady
TxReady
Data
Dclk
Plllock
01
ClkOut
TxReady
TxReady
Data
LowBat
TxReady
10
LowBat
LowBat
AutoMode
Data
LowBat
LowBat
TX
11
ModeReady
PllLock
TxReady
Data
PllLock
ModeReady
Table 1: Continuous Mode DIO Mappings