lmh0056sq National Semiconductor Corporation, lmh0056sq Datasheet - Page 9

• Manufacturer Part Number: lmh0056sq
• Description: Hd/sd Sdi Reclocker With 4 1 Input Multiplexer
• Manufacturer: National Semiconductor Corporation

LOCK DETECT
Control Inputs and Indicator
Outputs
SERIAL DATA INPUT SELECTOR
The Serial Data Input Selector (SEL [1:0]) allows the user to
select the active input channel. Table 2 shows the input
selected for a given state of SEL [1:0].
LOCK DETECT
The Lock Detect (LD) output, when high, indicates that data
is being received and the PLL is locked. LD may be con-
nected to the MUTE input to mute the data and clock outputs
when no data signal is being received. See Table 3.
X
X
0
1
0
1
1
SEL [1:0] Code
TABLE 2. Data Input Select Codes
00
01
10
11
(Continued)
OUTPUT MUTE
LOCK DETECT
LOCK DETECT
LOCK DETECT
1
1
0
1
Selected Input
BYPASS/AUTO BYPASS
SDI0
SDI1
SDI2
SDI3
TABLE 3. Control Functionality
X
X
0
0
0
1
1
9
PLL unlocked, reclocker bypassed
PLL locked to supported data rate, reclocker not bypassed
Outputs muted
Outputs muted
PLL locked to supported data rate, reclocker not bypassed
PLL locked to supported data rate, reclocker bypassed
Outputs not muted, reclocker bypassed
MUTE
The MUTE input, when low, mutes the serial data and clock
outputs. It may be connected to Lock Detect or externally
driven to mute or un-mute the outputs. If MUTE is connected
to LD, then the data and clock outputs are muted when the
PLL is not locked. This function overrides the Bypass func-
tion: see Table 3. MUTE has an internal pull-up device to
enable the output by default.
BYPASS/AUTO BYPASS
The Bypass/Auto Bypass input, when high, forces the device
to output the data without reclocking it. When this input is
low, the device automatically bypasses the reclocking func-
tion when the device is in an unlocked condition or the
detected data rate is a rate which the device does not
support. See Table 3. BYPASS/AUTO BYPASS has an in-
ternal pull-down device.
DEVICE STATUS
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