SI2107-D-FM Silicon Laboratories Inc, SI2107-D-FM Datasheet - Page 33

• Manufacturer Part Number: SI2107-D-FM
• Manufacturer: Silicon Laboratories Inc

Specifications of SI2107-D-FM

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

continues the process. The message length must also
be reprogrammed to indicate how many more bytes
remain to be sent. The interval between FIFO reads is
typically 13.5 ms.
To support cascaded DiSEqC devices, it may be
necessary to repeat commands. Repeated commands
should be separated by at least 100 ms to ensure that
the far-end device is connected to the signaling path. To
facilitate the required 100 ms delay, a four byte
command
commands.
6.7.3.2. DiSEqC 2.x Two-Way Communication
Two-way communication is supported via DiSEqC 2.x-
compliant messages. When the seventh bit in the
framing byte of an outgoing message is set to 1, the
device anticipates a response and monitors the line for
up to 150 ms for an incoming message. If no message
is detected during the 150 ms monitoring period, the
MSGTO bit is asserted to indicate the time-out
condition. A DiSEqC reply message typically consists of
a single framing byte and optionally one or more data
bytes as shown in Figure 20.
When a complete message has been received (one or
more bytes followed by 4 ms of silence), the MSGR bit
is asserted. Should parity errors exist in the received
message, the MSGPE flag is also asserted. If the
received message is longer than 6 bytes, the FIFO full
bit, FF, is asserted to indicate that a byte has been
written to FIFO6. The LNB control module writes the
next byte to FIFO1. The length of the received message
is recorded in the MSGRL register.
6.7.4. LNB Signaling Modes
The LNB signaling modes are described in the following
sections.
6.7.4.1. Automatic LNB Messaging Mode
The Si2107/08/09/10 LNB Signaling Controller can fully
manage the generation and sequencing of all LNB
commands. The device is configured in this mode by
appropriately programming the LNB Messaging mode
register, LNBM. To initiate a message sequence, the
user should first program LNB voltage selection (LNBV),
continuous tone enable (LNBCT), tone burst type
(LNBB), and DiSEqC message parameters (MMSG,
MSGL,
sequence start bit, LNBS, must be set to start the
automated
automatically allocates the required delays between
FRAMING
and
Figure 20. DiSEqC Reply Format
can
transmission
FIFO1..6).
P
be
DATA
inserted
Subsequently,
sequence.
P
between
DATA
The
the
repeated
device
LNB
P
Rev. 1.0
each signaling method. Prior dc voltage levels and
continuous tones, if present, persist until the sequence
is initiated. A typical sequence is shown in Figure 21.
Multiple messages can be sent in a sequential manner
by setting the MMSG bit. When this bit is set, the LNB
control module delays continuous tone and tone burst
commands until all messages in the sequence have
been sent. After the current message is transmitted, the
MMSG bit is automatically cleared. The tone burst can
be disabled as part of this sequence depending on the
setting of BRST_DS.
When the sequence has completed, the device clears
the LNB sequence start bit, LNBS, automatically. Note
that, when operating in this mode, the DRC pin is high
while transmitting and low while receiving.
6.7.4.2. Step-by-Step LNB Messaging Mode
By appropriately programming the LNB Messaging
Mode register, LNBM, the device allows for individual
control of each signaling method by the host. In this
mode, the LNB voltage, LNBV, and LNB continuous
tone enable, LNBCT, take effect once they are set
without waiting for the user to set the LNB sequence
start bit, LNBS.
The DiSEqC message uses the LNBS bit to start
transmission and behaves the same as in Automatic
LNB Messaging Mode. However, the guard intervals
between each signaling method (LNB voltage change,
DiSEqC message, tone burst, and continuous tone
resumption) are controlled by the host.
In this mode, the tone burst should be implemented by
using a 1-byte DiSEqC message of all 0s or all 1s
programmed into FIFO1. The device uses appropriate
modulation for the tone burst; i.e., when FIFO1 is
programmed to 00h (rather than a DiSEqC-compliant
modulation for a '00h' byte), no tone is generated. Also,
the device does not expect a reply if FIFO1 is
programmed to FFh; i.e., the assertion of bit7 is not
considered a request for the peripheral to reply in step-
by-step LNB messaging mode.
6.7.4.3. Manual LNB Messaging Mode
The manual LNB messaging mode provides the
maximum level of signaling flexibility but at the expense
of increased software interaction. The device is
configured in this mode by appropriately programming
the LNBM register. The continuous tone, tone burst, and
messaging controls are not functional in this mode.
When the tone format bit, TFS, is programmed for use
of the internal oscillator, assertion of the TT bit
modulates the output of the internal tone generator on
the TGEN pin, and the TR bit records the envelope of a
tone presented to the TDET pin.
Si2107/08/09/10
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