SAA7201H Philips Semiconductors, SAA7201H Datasheet - Page 19

• Manufacturer Part Number: SAA7201H
• Description: Integrated MPEG2 AVG decoder
• Manufacturer: Philips Semiconductors

Philips Semiconductors
1997 Jan 29
handbook, full pagewidth
The chroma up-conversion unit converts the MPEG
4 : 2 : 0 format into the at the output required
4 : 2 : 2 format. This vertical up-conversion is performed
by a simple 8-phase interpolation between two adjacent
lines.
The mixer units combine MPEG video with graphics and
cursor information in two steps. In a first step the MPEG
decoded information is mixed with graphical information.
Mixing can be done at pixel basis in 64 steps and is
controlled by the internally implemented colour look up
table. In a second step, the video plus graphics can be
mixed in 4 steps with the internally generated cursor.
The output formatting unit performs two main tasks, i.e.
synchronization and formatting. Synchronization is
characterized by three signals being horizontal (H),
vertical (V) and field parity (FP), all having
programmable length and polarity.
Integrated MPEG2 AVG decoder
(example)
GRPH
HREF
CREF
YUV
CLK
'128'
Fig.12 Timing diagram of graphics information output.
'16'
U 0
19
Additionally the full YUV bus can be set to a HIGH
impedance state under control of the signal YUV_ENA.
This might be useful for multiplexing the MPEG decoder
output with any other signal source on static basis.
Since the decoder can operate in master or slave mode,
the synchronization signals can be generated by the
decoder or should be delivered by an external device.
In both cases the length and polarity should be
programmed internally.
The video output samples are supplied in a multiplexed
YUV format to the output. Next to this byte wide YUV
stream, which can directly be supplied to most
commercially available composite video encoder ICs,
three additional signals are delivered at the output.
HREF indicates all active samples; CREF can flag any
combination of pixels: U, V, Y
flags all the pixels inside a graphical box.
Y 0
V 0
odd
Objective specification
and/or Y
Y 2
SAA7201
even
MGD332
; GRPH