HMP8112CN HARRIS [Harris Corporation], HMP8112CN Datasheet - Page 9

• Manufacturer Part Number: HMP8112CN
• Description: NTSC/PAL Video Decoder
• Manufacturer: HARRIS [Harris Corporation]

(4 x f
(4 x 3.579545MHz) / 27MHz = 0.5302895
This value must be loaded to correctly separate and decode
the video signal. A default Chroma PLL Value is used after a
system RESET is applied. The default assumes a CLK of
27MHz and NTSC as the video standard. The default value
is 0.5302895. An ideal 4xf
NTSC and 1135 for PAL.
The Output Sample rate converter is locked to the horizontal
line frequency and is used to spatially align pixels in a field.
The LOCKED flag signals when the phase locked loop is
within a 4 pixel range of the horizontal sync edge. When
line errors exceed that range the LOCKED flag is cleared.
VIDEO INPUT
LOW TIME
COUNTER
VSYNC
FIELD
PAL B, D, G, H, I
VIDEO INPUT
LOW TIME
COUNTER
VSYNC
FIELD
STANDARD
Combination
NTSC M
SC
Special
PAL M
PAL N
PAL N
)/CLK = Chroma PLL Value
VSYNC DETECT
VSYNC DETECT
4.43361875MHz
4.43361875MHz
3.58205625MHz
THRESHOLD
THRESHOLD
SUBCARRIER
‘EVEN’ FIELD
3.579545MHz
3.579545MHz
COLOR
f
‘ODD’ FIELD
SC
SC
line should have 910 pixels for
FIGURE 7. VSYNC TIMING AND THE EVEN TO ODD TRANSITION
FIGURE 8. VSYNC TIMING AND THE ODD TO EVEN TRANSITION
O
O
V
V
TABLE 2. COMPATIBLE VIDEO INPUT STANDARDS
NUMBER OF
FIELDS PER
SECOND
60Hz
50Hz
60Hz
50Hz
50Hz
HMP8112
NUMBER OF
VERTICAL
LINES
6.5 LINES
525
625
525
625
625
9
In cases where VCRs are used in Pause, Fast Forward or
Fast Reverse, lines are typically dropped or added by the
VCR. In a worst case scenario a VCR line tolerance will vary
by 8%. The standard detect logic checks the line count
against the given standard to determine an error. VCRs in
trick mode cannot cause a standard error. With an NTSC
standard VCR the number of lines in a field should not
exceed 285. Greater than 285 lines in a field is interpreted
as a PAL video source. An ideal NTSC source should have
262.5 lines per field and a PAL source should have 312.5
lines per field.
The HMP8112 can detect a STANDARD Error that signals
when the video received does not match the standard that
was programmed into the Video Input Control Register. This
6.5 LINES
FREQUENCY
( 0.0003%)
( 0.0003%)
( 0.02%)
( 0.15%)
( 0.15%)
15,734
15,625
15,750
15,625
15,750
LINE
BANDWIDTH
NOMINAL
4.2MHz
5.0MHz
4.2MHz
4.2MHz
4.2MHz
SETUP TO
BLACK
BLANK
7.5 IRE
7.5 IRE
7.5 IRE
7.5 IRE
0 IRE