LMH0070SQX National Semiconductor Corporation, LMH0070SQX Datasheet - Page 2

• Manufacturer Part Number: LMH0070SQX
• Description: The LMH0040 family of products provide a very simple 5:1 serializer and transmitter function, intended to be paired with an FPGA host which will format the data appropriately such that the output of the LMH0040 will be compliant with the output requi
• Manufacturer: National Semiconductor Corporation

www.national.com
Device Operation
The LMH0040 serializer is used in digital video signal origi-
nation equipment. It is intended to be operated in conjunction
with an FPGA host which preprocesses data for it, and then
provides this data over the five bit wide datapath. Provided
the host has properly formatted the data for the LMH0040, the
output of the device will be compliant with DVB-ASI, SMPTE
259M-C, SMPTE 292M or SMPTE 424M depending upon the
output mode selected.
DVB_ASI Mode
The LMH0040 has a special mode for DVB-ASI. In this mode,
the input signal on TX4+/TX4- is treated as a data valid bit, if
LMH0340
LMH0040
LMH0070
LMH0050
Device
SMPTE 424M
Support
X
SMPTE 292M
Support
X
X
X
TABLE 1. Feature Table
SMPTE 259M
Support
2
high, then the four bit nibbles from TX0–TX3 are taken to form
an 8 bit word, which is then converted to a 10 bit code via an
internal 8b10b encoder and this 10 bit word is serialized and
driven on the output. The nibble taken in on the rising edge of
the clock is the most significant nibble and the nibble taken in
on the falling edge is the least significant nibble. If TX4+/TX4-
is low, then the input on TX0–TX3 are ignored and the 10b
idle character is inserted in the output stream.
X
X
X
X
DVB-ASI Support SMPTE Compliant
X
X
X
X
cable driver
X
X
X