saa4996h NXP Semiconductors, saa4996h Datasheet - Page 20

• Manufacturer Part Number: saa4996h
• Description: Motion Adaptive Colour Plus And Control Ic Macpacic For Palplus
• Manufacturer: NXP Semiconductors

Philips Semiconductors
7.12
7.12.1
The input is a 4:1:1 sequential 4-bit wide UV signal with a
16 MHz clock frequency. Originally the U and V signals
were 8 bits wide with a sampling frequency of 4 MHz each.
The range is 0 90 in two’s complement format for
U and V.
7.12.2
The Motion Adaptive Colour Plus technique is also applied
in the chrominance processing to remove the luminance
part from the incoming demodulated UV signal.
In the modulated domain the chrominance signal can be
generated by subtracting the odd and even field data due
to the 180 phase difference of the colour subcarrier.
The colour decoder eliminates the phase difference of the
chrominance signals, but now the luminance signals will
obtain the phase difference of 180 .
By adding the odd and even field data, the cross-colour
free chrominance signal (UVifa) is generated.
This processing will work successfully in the film mode,
because scanned film material is motionless within the two
fields of one frame. In the camera mode, where each field
represents an individual picture, a motion detector fades
down the chrominance high-pass component if motion is
detected.
When chrominance motion occurs, the encoder fades
down the high-pass luminance signal. In that event, the
motion detector in the decoder will switch the chrominance
part from intra frame average processing to the incoming
data.
1996 Oct 28
handbook, full pagewidth
Motion Adaptive Colour Plus And Control
IC (MACPACIC) for PALplus
Chrominance
I
C
NPUT RANGE
HROMINANCE PROCESSING
UV_ADC
UV_FM1
(even)
(odd)
UVifa
Fig.9 Chrominance processing.
0
1
0
1
MUX
MUX
CS
from motion
detector
UV_TO_FM4
to motion detector
LM
LM
20
Odd and even field data are multiplexed and connected to
the output of MACPACIC.
The chrominance processing has two input branches (see
Fig.9). One input branch is the direct chrominance input
path from the ADC. The other input branch is the output of
the field memory FM1. The odd field of a frame is stored in
the field memory FM1. In the even field of a frame the
delayed odd field and the incoming even field are
processed with the motion adaptive colour plus algorithm
to the cross-colour free chrominance output data.
By adding the incoming chrominance signals of the odd
and even fields, the intra frame average chrominance
signal (UVifa) is generated.
For the chrominance motion detector this signal is stored
after formatting in the memory FM4 (UV_TO_FM4).
7.12.3
The output data rate is 32 MHz for MACPACIC in
combination with VERIC and 16 MHz for stand-alone
MACPACIC or in the MultiPIP mode.
In the MultiPIP mode the chrominance data from the ADC
(UV_ADC) is switched directly to the output UV_MA.
In the bypass mode the chrominance data processing is
switched off and the multiplexed odd and even field data
are connected to the MACPACIC output.
7.12.4
The range is 0 90 in two’s complement format for
U and V.
UV_ADC
UV_FM1
MUX
O
O
UTPUT SIGNALS
UTPUT RANGE
MUX
UV_TO_FM1
UV_out
MHA299
Preliminary specification
SAA4996H