SI2109-D-FMR Silicon Laboratories Inc, SI2109-D-FMR Datasheet - Page 36

• Manufacturer Part Number: SI2109-D-FMR
• Manufacturer: Silicon Laboratories Inc

Specifications of SI2109-D-FMR

• Operating Temperature (min): 0C
• Operating Temperature (max): 70C
• Operating Temperature Classification: Commercial
• Lead Free Status / Rohs Status: Supplier Unconfirmed

Si2107/08/09/10
Important: It is highly recommended that the registers
in Step 2 be programmed with default values provided
by Silicon Laboratories. Refer to “AN298: Si2107/08/09/
10
Software”, for the recommended values. The values are
documented in the QuickScan section of the application
note. Silicon Laboratories has tested QuickScan under
real world conditions in a number of countries and the
recommended values provide the best performance.
3. Clear the following Host Control Register bits.
Important: These bits should be returned to their
default settings (allowing host control) if the user wants
to tune to individual channels following blindscan for
single channel acquisition.
4. Set BS_START in the Blind Scan Control Register. This
5. Wait for either BSDA (or interrupt BSDA_I) or BSDO (or
6. Take the following actions depending on which condition is
RF(MHz) = BS_CTF x 10 + {BS_FTF(decimal) + CFER
(decimal)} x BS_ADCSR
36
e. 2 dB Bandwidth Threshold Register. This sets the
f.
g. Inband Power Threshold Register. This sets the
a. SR_CTRL_HOST
b. ADCSR_CTRL_HOST
c.
d. FTF_CTRL_HOST
initiates the blindscan process.
interrupt BSDO_I) to be set.
present:
a. When BSDA (or BSDA_I) is set: the device has found
Application
3 dB Bandwidth Threshold Register. This sets the
CTF_CTRL_HOST
tolerance level for determination of the 1 dB
bandwidth for a detected channel.
tolerance level for determination of the 2 dB
bandwidth for a detected channel.
tolerance level for determination of the 3 dB
bandwidth for a detected channel.
threshold for determining the drop in power in a
detected channel to determine the channel bandwidth.
a potential DVB-S or DSS (depending on the part's
operating mode) channel. The host can read out:
i. BS_CTF, BS_FTF, CFER, and BS_ADCSR
to determine the channel's RF frequency
from the following formula:
format of <15,14> and CFER with a fixed
format of <16,15> are 2's complement
numbers which need to be converted into
decimal numbers first.
Note: The registers BS_FTF with a fixed
Programming
Interface
Example
Rev. 1.0
Symbol Rate (MBaud) = SREST x BS_FS / 2^23
7. Repeat Steps 1 through 6 with the change in values for the
8. End of blindscan operation. The final set of estimates for
6.10. Sleep Mode Operation
A low power mode can be enabled by setting the PDE
bit to 1. In Sleep mode, the System Mode register can
be read and written to, but all other registers can be
read only. The Sleep mode is exited by setting the PDE
bit to 0.
b. When BSDO (or BSDO_I) is set: the blindscan
a. Set SRMIN to 12.5 MBaud.
b. Keep SRMAX the same value from the first pass.
c.
d. Set 2 dB Bandwidth Threshold Register to the second
following parameters if the Symbol Rate search range is
below 12.5 MBaud.
RF center frequencies and associated symbol rates can
be used by the host to lock to the detected channels to
obtain channel information such as Channel ID for
example. Also at this point channels falsely identified
during blindscan can be rejected upon failure to lock.
Set Inband Power Threshold Register to the second
operation is complete within the RF and symbol rate
search ranges. The device automatically clears
BS_START.
recommended default value.
recommended default value.
ii. SREST to determine the channel's symbol
iii. Upon reading these registers, the host
Where BS_FS = BS_ADCSR x 1 MHz
rate estimate from the following formula:
should clear the BSDA & BSDA_I bits. Go
back to Step 6.