SI4840-A10 Datasheet, PDF (17/26 Pages) Silicon Laboratories – BROADCAST ANALOG TUNING DIGITAL DISPLAY AM/FM/SW RADIO RECEIVER

Si4840/44-A10
5. Commands and Properties
Table 11. Si4840/44-A10 FM Receiver Command Summary
Cmd
Name
Description
0xE0
ATDD_GET_STATUS Get tune freq, band and etc status of the device
0xE1
ATDD_POWER_UP
Power up device, band selection and band properties setup
0xE2
ATDD_AUDIO_MODE Audio output mode: get/set audio mode and settings
0x10
GET_REV
Returns the revision information of the device.
0x11
POWER_DOWN
Power down device.
0x12
SET_PROPERTY
Sets the value of a property.
0x13
GET_PROPERTY
Retrieve a property's value.
Note: The si4840/44 has its own power up and get status commands which is different from previous si47xx tuner parts. To
differentiate, we use “ATDD_POWER_UP” and ATDD_GET_STATUS to denote the ATDD specific commands instead
of the general si47xx “POWER_UP” and “STATUS” commands
Table 12. Si4840/44-A10 FM Receiver Property Summary
Prop
0x1100
0x1300
0x1301
0x1302
0x1303
0x1207
0x1800
0x1801
0x4000
0x4001
0x4002
0x4003
Name
Description
Default
FM_DEEMPHASIS
Sets deemphasis time constant. Default is 75 μs.
0x0002
FM_SOFT_MUTE_RATE Sets the attack and decay rates when entering and leaving 0x0040
soft mute.
FM_SOFT_MUTE_SLOPE Configures attenuation slope during soft mute in dB attenua- 0x0002
tion per dB SNR below the soft mute SNR threshold. Default
value is 2.
FM_SOFT_MUTE_
MAX_ATTENUATION
Sets maximum attenuation during soft mute (dB). Set to 0 to 0x0010
disable soft mute. Default is 16 dB.
FM_SOFT_MUTE_
SNR_THRESHOLD
Sets SNR threshold to engage soft mute. Default is 4 dB.
0x0004
FM_STEREO_IND
Sets the blend threshold for stereo indicator. Default value is 0x9F
_BLEND_THRESHOLD ^{band dependent (either 0x9F or 0xB2)}
0xB2
FM_BLEND_RSSI_
STEREO_THRESHOLD
Sets RSSI threshold for stereo blend. (Full stereo above
threshold, blend below threshold.) To force stereo, set this to
0. To force mono, set this to 127. Default value is 49 dBμV.
0x0031
FM_BLEND_RSSI_
MONO_THRESHOLD
Sets RSSI threshold for mono blend (Full mono below
threshold, blend above threshold). To force stereo, set this to
0. To force mono, set this to 127. Default value is band
dependent (either 8 or 7).
0x0008
0x0007
RX_VOLUME
Sets the output volume.
0x003F
RX_HARD_MUTE
Mutes the audio output. L and R audio outputs may be
muted independently.
0x0000
RX_BASS_TREBLE
Sets the output bass/treble level
0x0004
RX_ACTUAL_VOLUME Read the actual output volume
0x003F
Rev.1.0
17