MC68181 Datasheet, PDF (107/119 Pages) Freescale Semiconductor, Inc – Advance Information ROAMING FLEX chip SIGNAL PROCESSOR

Freescale Semiconductor, Inc.
MC68181
Receiver Control
When the FLEXchip IC warms up the receiver in response to one of these host
requests, the first warm up setting, if enabled, is applied to the receiver control lines
for the amount of time programmed for that setting. Each subsequent warm up
setting is applied to the receiver control lines for their corresponding time until a
disabled warm up setting is found. Once a disabled warm up setting is found, the
“3200sps Sync Setting” (for ON and SND warm ups) or the “1600sps Sync Setting”
(for SAS warm ups) is applied to the receiver control lines and the decoder does not
expect valid signal until after the “3200sps Sync Warm Up Time” (for ON, SND, and
SAS warm ups) has expired. Figure C-2 shows the receiver warm up sequence when
the host initiates a warm-up sequence, and when all warm up settings are enabled.
Receiver
Control
Off
Line Setting
Warm Up
Time 1
Warm Up
Setting 1
Warm Up
Time 2
Warm Up
Setting 2
Warm Up
Time 3
Warm Up
Setting 3
Warm Up
Time 4
Warm Up
Setting 4
Warm Up
Time5
Warm Up
Setting 5
3200 sps
Sync
Warm Up
Time
3200 sps
Sync Setting
Possible
LOBAT
Check
Possible
LOBAT
Check
Possible
LOBAT
Check
Possible
LOBAT
Check
Possible
LOBAT
Check
Possible
LOBAT EXTS1 & EXTS0
Check signals are
expected to be
valid here.
AA1237
Figure C-2 Host Initiated Receiver Warm Up Sequence
Receiver Shut Down Sequence
The FLEXchip IC allows for up to three steps associated with shutting down the
receiver. When the FLEXchip IC decides to turn off the receiver, the first shut down
setting, if enabled, is applied to the receiver control lines for the corresponding shut
down time. At the end of the last used shut down time, the “Off” setting is applied to
the receiver control lines. If the first shut down setting is not enabled, the FLEXchip
IC will transition directly from the current “On” setting to the “Off” setting.
Figure C-3 shows the receiver turn off sequence when all shut down settings are
enabled.
If the receiver is on or being warmed up when the decoder is turned off (by clearing
the ON bit in the Control Packet), the FLEXchip IC will execute the receiver
shutdown sequence. If the FLEXchip IC is executing the shut down sequence when
the FLEXchip IC is turned on (by setting the ON bit in the Control Packet), the
FLEXchip IC will complete the shut down sequence before starting the warm up
sequence.
MOTOROLA
MC68181 Technical Data Sheet
C-3
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