HDSP-390X Agilent(Hewlett-Packard), HDSP-390X Datasheet - Page 17

• Manufacturer Part Number: HDSP-390X
• Description: 20 mm (0.8 inch) Seven Segment Displays
• Manufacturer: Agilent(Hewlett-Packard)

Tx I/O Definition (cont’d.)
INV
LOCKED
LOOPEN
LOUT
LOUT*
M20SEL
MDFSEL
RFD
RST*
STRBIN
STRBIN*
Name
Pin
25
75
16
14
15
73
74
65
34
8
9
O-ECL
O-ECL
O-BLL
O-ECL
I-ECL
I-ECL
I-ECL
I-ECL
I-H50
Type
Invert Signal: A high value of INV implies that the current frame is
being sent inverted to maintain long-term DC balance. With a buffer,
or pulled down with a 1K resistor to V
is useful as an aid to analyzing the serial output stream with an
oscilloscope.
Loop In-lock Indication: This signal indicates the lock status of the
Tx PLL. A high value indicates lock. This signal is normally connected
to the SMTRST1 reset input of the Rx state machine to force the link
into the start-up state until the Tx PLL has locked. This signal may
give multiple false-lock indications during the acquisition process, so
should be debounced if it is used for any other purpose than to drive
the Rx chip.
Loop Back Control: Input which controls whether the DOUT,
DOUT*, or the LOUT, LOUT* outputs are currently enabled. If active,
LOUT, LOUT* are enabled. The unused output is powered down to
reduce dissipation.
Loop Back Serial Data Output: Output used when LOOPEN is
active. Typically this output will be used to drive the LIN, LIN* inputs
of the Rx chip.
16 or 20 Bit Word Select: When this signal is high, the link operates
in 20 Bit data transmission mode. Otherwise, the link operates in
16 Bit mode.
Select Double Frame Mode: When this signal is high, the PLL
expects a 1/2 speed parallel clock at STRBIN. The chip then internally
multiplies this clock and produces a full-rate parallel clock at
STRBOUT. Note that the phase relationship of STRBIN to STRBOUT
and the sampling point change with asserting MDFSEL, as shown in
the Tx timing diagram. This feature is provided so that either a 40 bit
or 32 bit word can be easily transmitted as two 20, or two 16 bit
words. When MDFSEL is low, the PLL expects a full-rate parallel
clock at STRBIN.
Ready for Data: Output to tell the user the Link is ready to
transmit data. This pin is a retimed version of the ED input, which is
driven by the Rx chip state machine controller.
Chip Reset: This active-low pin initializes the internal chip registers.
It should be asserted during power up for a minimum of 5 parallel-
rate clock cycles to ensure a complete reset.
Data Clock Input: When EHCLKSEL is low, this input is phase
locked and multiplied to generate the high speed serial clock. The chip
expects a clock frequency which is equal to the input frame rate if
MDFSEL (double frame mode) is low, and 1/2 the frame rate if
MDFSEL is high. When EHCLKSEL is high, the PLL is bypassed,
and STRBIN directly becomes the high speed serial clock. Refer to
the Tx Timing diagram for the phase relationship between STRBIN,
data and STRBOUT.
Signal
EE
and ac coupled, this signal
589