Philips EM5A NTSC Service Manual page 126

Colour television
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EN 126
9.
EM5A NTSC
9.8.2
Block diagram
FILTERS
HA
VA
The 60 Hz YUV signals, coming from the HIP, are fed to the
PICNIC via an anti-aliasing filter.
The (AABB) frame frequency doubling is done by the PICNIC
(SAA4978, 160 pins QFP) together with a field memory
(MEM1.) This IC can handle most 120 Hz functions (except
Progressive Scan.)
The PICNIC has an internal CPU and a (small) integrated
ROM. The actual FBX7 software is located in an external ROM
(item 7711.) In order to limit the number of connections
between the PICNIC and the external ROM, a number of lines
are used twice. The lines A8 to A15 are fixed lines, while the
lines A0 to A7 are made switchable with the eight data lines of
the ROM. This is done via a Latch (item 7712), which is
controlled by pin 139 of the PICNIC (the ALE signal.)
Via bus 'C,' a digitalized signal is presented to FM1 (Field
Memory 1), which is used for the 60 to 120 Hz conversion. The
signal goes further via the data-bus to the FALCONIC. This IC
has the following functions:
Line flicker reduction.
Digital Noise Reduction (DNR.)
Progressive scan.
At the end, the digital YUV signals enter, via FM4 and FM5, the
Eagle IC.
This IC has the following functions:
Luminance Transient Improvement (LTI.)
Peaking.
Programmable number of lines.
Programmable number of pixels per line.
Circuit Descriptions and Abbreviation List
IC 7714
MS81V04160
MEM1
8UV
8Y
8UV
8Y
8UV
8Y
WE IE
RE D
BUS C
BUS D
ADC
ACTIVE
'HIGH'
.139
ALE
ACTIVE
'HIGH'
EN
A8...A15
IC 7711
M27C512
64k PROM
Figure 9-12 Block diagram FBX7
IC 7718
SAA4992
FALCONIC
8UV
8UV
8Y
8Y
IC 7722
IC 7723
MEM 5
MEM 4
8UV
8UV
8Y
8Y
IC 7724
EAGLE
IC 7713
SAA4978H
PICNIC
A0...A7
IC 7712
LATCH
IC
A0...A7
D0...D7
Demo mode (split screen.)
Improved color transients (CTI) and color enhancement
(TOPIC.)
Improved vertical zoom.
The digital YUV-signals from the Eagle go, via a passive output
filter, to the HOP.
9.8.3
PICNIC/FALCONIC (Diagram B3A and B3B)
The PICNIC has the following functions:
The ADC.
The DAC.
Interlaced to progressive scan conversion.
Dual screen compression
The Panorama mode.
Automatic Aspect Ratio Adaptation (AARA)
Color Transient Improvement (CTI)
The contrast improvement (Dynamic Contrast.)
All these functions are integrated in one IC: SAA4978H, 160
pins QFP.
ADC/DAC
Analog to Digital conversion is done with three identical 9-
bit ADCs.
Digital to Analog conversion uses three identical 10-bit
DACs.
IC 7717
MEM 2
100Hz
IC 7719
DIG
MEM 3
SCAN
HD
VD
YUV_EAGLE
FILTERS
DAC
HD
VD
CL 26532041_074.eps
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