Intersil Corporation HMP8116 Datasheet

SEMICONDUCTOR

ADVANCE DRAFT

April 1998

HMP8116

NTSC/PAL Video Decoder

Features

• (M) NTSC and (B, D, G, H, I, M, N, NC) PAL Operation

- Optional Auto Detect of Video Standard

- ITU-R BT.601(CCIR601) and Square Pixel Operation

• Digital Output Formats

- VMI Compatible

- 8-bit, 16-bit 4:2:2 YCbCr

- 15-bit (5,5,5), 16-bit (5,6,5) RGB

- Linear or Gamma-Corrected

- 8-bit BT.656

• Analog Input Formats

- Three Analog Composite Inputs

- Analog Y/C (S-video) Input

• “Raw” (Oversampled) VBI Data Capture

• “Sliced” VBI Data Capture Capabilities

- Closed Captioning

- Widescreen Signalling (WSS)

- BT.653 System B, C and D Teletext

- NABTS (North American Broadcast Teletext)

- WST (World System Teletext)

• 2-Line (1H) Comb Filter Y/C Separator

• Fast I

• Two 8-Bit ADCs

2

C Interface

Description

The HMP8115 is a high quality NTSC and PAL decoder with
internal A/D converters. It is compatible with NTSC M, PAL
B, D, G,H, I, M, N, and combination N (N

Both composite and S-video (Y/C) input formats are sup­ported. A 2-line comb filter plus a user-selectable chromi­nance trap filter provide high quality Y/C separation. User
adjustments include brightness, contrast, saturation, hue,
and sharpness.

Data during the vertical blanking interval (VBI), such as
closed captioning, widescreen signalling and teletext, may
be captured and output as BT.656 ancillary data. Closed
captioning and widescreen signalling information may also
be read out via the I

2

C interface.

) video standards.

C

Ordering Information

TEMP.

PART NUMBER

HMP8116CN 0 to 70 80 Ld PQFP Q80.14x20
HMPVIDEVAL/ISA Evaluation Board: ISA Frame Grabber

NOTES:

1. PQFP is also known as QFP and MQFP.

2. Evaluation Board and Reference Design descriptions are in the
Applications section.

RANGE (oC) PACKAGE PKG.NO.

Applications

• Multimedia PCs

• Video Conferencing

• Video Compression Systems

• Video Security Systems

• LCD Projectors and Overhead Panels

• Related Products

- NTSC/PAL Encoders: HMP815x, HMP817x

- NTSC/PAL Decoders: HMP8112A

• Related Literature

- AN9644: Composite Video Separation Techniques

- AN9716: Widescreen Signalling

- AN9717: YCbCr to RGB Considerations

- AN9728: BT.656 Video Interface for ICs

- AN9738: VMI Video Interface for ICs

CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures.
Copyright

© Harris Corporation 1998

1

File Number 4510

HMP8116HMP8116

Table of Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

External Video Processing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

ANALOG VIDEO INPUTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

ANTI-ALIASING FILTERS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Digitization of Video . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

A/D CONVERSION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

AGC AND DC RESTORATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

INPUT SIGNAL DETECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

VERTICAL SYNC AND FIELD DETECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Y/C SEPARATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

INPUT SAMPLE RATE CONVERTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

COMB FILTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

CHROMA DEMODULATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

OUTPUT SAMPLE RATE CONVERTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

CLK2 INPUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Digital Processing of Video . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

UV to CbCr Conversion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

DIGITAL COLOR GAIN CONTROL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

COLOR KILLER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Y PROCESSING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

CbCr

Processing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

YCbCr

Output Format Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

RGB OUTPUT FORMAT PROCESSING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

BUILT-IN VIDEO GENERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Pixel Port Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

HSYNC AND VSYNC TIMING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

FIELD TIMING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

BLANK AND DVALID TIMING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

PIXEL OUTPUT PORT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

8-BIT YCbCr OUTPUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

16-BIT YCbCr, 15-BIT RGB, OR 16-RGB OUTPUT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

8-BIT BT.656 OUTPUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Advanced Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

CLOSED CAPTIONING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

WIDESCREEN SIGNALLING (WSS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

BT.656 ANCILLARY DATA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

BT.656 CLOSED CAPTIONING AND WIDE SCREEN SIGNALLING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

TELETEXT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

REAL TIME CONTROL INTERFACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Host Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

HMP8116 Control Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Applications Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

PCB LAYOUT CONSIDERATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

EVALUATION BOARD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

RELATED APPLICATION NOTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

2

Functional Block Diagram

HMP8116

RATE

OUTPUT

SAMPLE

CONVERTER

USER

ADJUST.

RGB

LOGIC

VBIVALID

HSYNC

BLANK

TIMING

OUTPUT

AND

DVALID

FIFO

P[15:0]

VBI STATUS BITS

ADC

8-BIT

VBI

DETECTION &

DECODING LOGIC

USER

ADJUST

TRAP

COLOR

Y/C

SEPARATION

COLOR

ADJUST

COLOR

DEMODULATION

INPUT

RATE

SAMPLE

CONVERTER

HSYNC

DETECT

PLL

CHROMA

ADC

8-BIT

LINE

LOCK

VSYNC

DETECT

PLL

SCL

SDA

CONTROL

INTERFACE AND

MICROPROCESSOR

LOCKED

VSYNC

FIELD

INTREQ

RESET

FILTER

EXTERNAL

ANTIALIASING

YIN

YOUT

CVBS1

-

+

MUX

INPUT

CVBS2

CVBS3/(Y)

BLACK LEVEL

WHITE PEAK LEVEL

DIGITAL COMPARATORS

AND

AGC

CLAMP

L_CAP

SYNC LEVEL

LOGIC

3

DIGITAL COMPARATOR

LOGIC

CLAMP

CLAMP

AND

GAIN

C_CAP

CONTROL

-

+

C

FILTER

EXTERNAL

ANTIALIASING

Functional Block Diagram

(Continued)

CLK

CHROMA
PLL NCO

CLK TO

4FSC RATIO

C,CVBS

DAT A

LINE
DELAY
COMB
FILTER

CHROMA

PLL LOOP

FILTER

C DATA

DEMODULATOR

CHROMA

CR[7:0]

C

M
U
X

C,CVBS

DAT A

(24.54, 27.0 or 29.5MHz)

4FSC

CLOCK

4

INPUT

SAMPLE

RATE

Y,CVBS

CONVERTER

Y DATA

Y DATA

Y DATA

M
U
X

Y DATA

HUE

ADJUST

AGC

ADJUST

U,V

HORIZONTAL

AND VERTICAL

SHARPNESS

ADJUST

CHROMA

PHASE

DETECTOR

SATURATION

ADJUST

CHROMA

TRAP

VSYNC

DETECT

U, V TO CbCr

COLOR

SPACE
CONVERTER
AND COLOR

KILLER

FIELD
VSYNC

GENLOCK LOSS

LP FILTER

ENABLE

LINE LOCKED

PLL LOOP FILTER

LINE LOCKED

NCO

CbCr

OUTPUT

SAMPLE

RATE

CONVERTER

Y

HSYNC

DETECT

HSYNC

LOCKED

SYNC

STRIPPER,

BRIGHTNESS,

& CONTRAST

ADJUST

HMP8116

VBI DETECTION

& DECODING LOGIC

SHARPNESS

ADJUST

ENABLE

LP FILTER

ENABLE

M
U
X

HSYNC,VSYNC, BLANK,

FIELD, DVALID, VBIVALID

STANDARD

SELECT

P[15:0]

RGB

LOGIC

MUX MUX

OUTPUT

TIMING

AND

FIFO

HMP8116

Introduction

The HMP8116 is designed to decode baseband composite
or S-video NTSC and PAL signals, and convert them to
either digital YCbCr or RGB data. In addition to performing
the basic decoding operations, the HMP8116 includes hard­ware to decode different types of VBI data and to generate
digital video patterns for a blue screen, black screen and full
screen color bars.

The digital PLLs are designed to synchronize to all NTSC
and PAL standards. A chroma PLL is used to maintain
chroma lock for demodulation of the color information; a line­locked PLL is used to maintain vertical spatial alignment.
The PLLs are designed to maintain lock even in the event of
VCR headswitches and multipath noise.

The HMP8116 contains two 8-bit A/D converters and an I

2

interface for programming internal registers

External Video Processing

Before a video signal can be digitized the decoder has some
external processing considerations that need to be
addressed. This section discusses those external aspects of
the HMP8116.

ANALOG VIDEO INPUTS

The HMP8116 supports either three composite or two com­posite and one S-video input.

toration” section. After digitization, sample rate converters and
a comb filter are used to perform color separation and demod­ulation.

A/D CONVERSION

Video data is sampled at the CLK2 frequency then pro­cessed by the input sample rate converter. The output levels
of the ADC after AGC and DC restoration processing are:

(M) NTSC (B, D, G, H, I, N
(M, N) PAL PAL

white 196 196
black 66 59
blank 56 59
sync 0 0

C

AGC AND DC RESTORATION

The AGC amplifier attenuates or amplifies the analog video
signal to ensure that the blank level generates code 56 or 59
depending on the video standard. The difference from the
ideal blank level of 56 or 59 is used to control the amount of
attenuation or gain of the analog video signal.

DC restoration positions the video signal so that the sync tip
generates a code 0. The internal timing windows for AGC
and DC Restoration are show in Figure 3.

)

C

Three analog video inputs (CVBS 1-3) are used to select
which one of three composite video sources are to be
decoded. To support S-video applications, the Y channel
drives the CVBS 3 analog input, and the C channel drives
the C analog input.

The analog inputs must be AC-coupled to the video signals,
as shown in the Applications section.

ANTI-ALIASING FILTERS

An external anti-alias filter is required to achieve optimum
performance and prevent high frequency components from
being aliased back into the video image.

For the CVBS 1-3 inputs, a single filter is connected between
the YOUT and YIN pins. For the C input, the antialiasing filter
should be connected before the C input. A recommended fil­ter is shown in Figure 1.

R

YOUT YIN

FIGURE 1. RECOMMENDED ANTI-ALIASING FILTER

332

1

C

33pF

L

1

8.2uH
C

1

82pF

2

R

2

4.02K

Digitization of Video

Prior to A/D conversion, the video signal is DC restored and
gained to generate knownvideo levelsinto the digital process­ing logic. This process is addessed in the “AGC and DC Res-

VIDEO INPUT

AGC

DC RESTORE

FIGURE 2. AGC AND DC RESTORE INTERNAL TIMING

INPUT SIGNAL DETECTION

It is assumed there is no video input if a horizontal sync is
not detected for 16 consecutive lines. When no video has
been detected, nominal video timing is generated for the
previously detected or programmed video standard. A
maskable interrupt is included to flag when no video has
been detected (bit 6 of the INTERRUPT MASK register 0F
allowing for blue/black/color bar output modes to be enabled
if desired. The vertical sync interrupt can be used in deter­mining when a video signal is present on the currently
selected video mux input. Bit 0 of register 0F

is used to

H

enable vertical sync interrupts.

H

)

5

HMP8116

VERTICAL SYNC AND FIELD DETECTION

The vertical sync and field detect circuit uses a low time
counter to detect the vertical sync sequence in the video
data stream. The low time counter accumulates the low time
encountered during any sync pulse, including serration and
equalization pulses. When the low time count exceeds the
vertical sync detect threshold,
ately. FIELD is asserted at the same time that

VSYNC is asserted immedi-

VSYNC is
asserted. FIELD is asserted low for odd fields and high for
evenfields. Field is determined from the location in the video
line where VSYNC is detected. If VSYNC is detected in the
first half of the line, the field is odd. If VSYNC is detected in
the second half of a line, the field is even.

In the case of lost vertical sync or excessive noise that would
preventthe detection of vertical sync, the FIELD output will con­tinue to toggle. Lost vertical sync is declared if after 337 lines, a
vertical sync period wasnot detectedfor 1 or 3 (selectable)suc­cessivefields as specified bybit 2 of the GENLOCK CONTROL
register 04

. When this occurs, the PLLs are initialized to the

H

acquisition state.

Y/C SEPARATION

A composite video signal has the luma (Y) and chroma (C)
information mixed in the same video signal. The Y/C separa­tion process is responsible for separating the composite
video signal into these two components. The HMP8116 uti­lizes a comb filter to minimize the artifacts that are associ­ated with the Y/C separation process.

INPUT SAMPLE RATE CONVERTER

The input sample rate converter is used to convert video
data sampled at the CLK2 rate to a virtual 4xf
for comb filtering and color demodulation. An interpolating
filter is used to generate the 4xf

samples as illustrated in

SC

Figure 3.

INCOMING VIDEO SAMPLES

sample rate

SC

have a half-line vertical offset from the luma data. This may
be eliminated, vertically aligning the chroma and luma sam­ples, at the expenseof vertical resolution of the luma. Bit 0 of
the OUTPUT FORMAT register 02

controls this option.

H

CHROMA DEMODULATION

The output of the comb filter is further processed using a
patented frequency domain transform to complete the Y/C
separation and demodulate the chromanance.

Demodulation is done at a virtual 4xf

sample rate using

SC

the interpolated data samples to generate U and V data. The
demodulation process decimates by 2 the U/V sample rate.

OUTPUT SAMPLE RATE CONVERTER

The output sample rate converter converts the Y, U and V
data from a virtual 4xf

sample rate to the desired output

SC

sample rate (i.e., 13.5MHz). It also vertically aligns the sam­ples based on the horizontal sync information embedded in
the digital video data stream. The output sample rate is
determined by the selected video standard and whether
square or rectangular pixels are output. The output format is
4:2:2 forall modes exceptthe RGB modes which use a 4:4:4
output format.

CLK2 INPUT

Note that the color subcarrier is derived from CLK2. Any jitter
on CLK2 will be transferred to the color subcarrier, resulting
in color changes. Thus, CLK2 should be derived from a sta­ble clock source, such as a crystal. The use of a PLL to gen­erate CLK2 is not recommended. CLK2 must havea 50ppm
accuracy and at least a 60/40% duty cycle to ensure proper
operation.

The CLK2 clock rate must be one of the following frequen­cies:

24.54MHz

27.00MHz

29.50MHz

TIME

RESAMPLED VIDEO

TIME

4xf

SC

FIGURE 3. SAMPLE RATE CONVERSION

COMB FILTER

A 2-line comb filter, using a single line delay, is used to per­form part of the Y/C separation process. During S-video
operation, the Y signal bypasses the comb filter; the C signal
is processed by the comb filter since it is an integral part of
the chroma demodulator. During PAL operation, the chroma
trap filter should also be enabled for improved performance.

Since a single line store is used, the chroma will normally

The frequency of CLK2 must be 2x the desired output sam­ple rate. The values in table 1 below indicate the CLK2 clock
rate based on the video standard and pixel mode. The out­put sample rate for the given video standard and pixel mode
is half the CLK2 clock rate.z

TABLE 1. VIDEO STANDARD CLOCKRATE SELECTION

SUMMARY

ALLOWABLE CLK2

FREQUENCIES (MHz)

RECTANGULAR

VIDEO FORMAT

(M) NTSC 27.00 24.54

(B, D, G, H, I, N) PAL 27.00 29.50

(M) PAL 27.00 24.54

(N

) PAL 27.00 29.50

C

PIXEL MODE

SQUARE

PIXEL MODE

6

HMP8116

Digital Processing of Video

Once the luma and chroma have been separated the
HMP8116 then performs programmable modifications (i.e.
contrast, coring, color space conversions, color AGC, etc.) to
the decoded video signal.

UV TO CbCr CONVERSION

The baseband U and V signals are scaled and offset to gen­erate a nominal range of 16-240 for both the Cb and Cr data.

DIGITAL COLOR GAIN CONTROL

There are four types of color gain control modes available:
no gain control, automatic gain control, fixed gain control,
and freeze automatic gain control.

If “no gain control” is selected, the amplitude of the color dif­ference signals (CbCr) is not modified, regardless of varia­tions in the color burst amplitude. Thus, a gain of 1x is
always used for Cb and Cr.

If “automatic gain control” is selected, the amplitude of the
color difference signals (CbCr) is compensated for variations
in the color burst amplitude. The burst amplitude is averaged
with the two previous lines having a color burst to limit line­to-line variations. A gain of 0.5x to 4x is used for Cb and Cr.

If “fixed gain control” is selected, the amplitude of the color
difference signals (CbCr) is multiplied by a constant, regard­less of variations in the color burst amplitude. The constant
gain value is specified by the COLOR GAIN register 1C
gain of 0.5x to 4x is used for Cb and Cr. Limiting the gain to
4x limits the amount of amplified noise.

If “freeze automatic gain control” is selected, the amplitude
of the color difference signals (CbCr) is multiplied by a con­stant. This constant is the value the AGC circuitry generated
when the “freeze automatic gain” command was selected.

COLOR KILLER

If “enable color killer” is selected, the color output is turned
off when the running average of the color burst amplitude is
below approximately 25% of nominal for four consecutive
fields. When the running average of the color burst ampli­tude is aboveapproximately 25% of nominal for four consec­utive fields, the color output is turned on. The color output is
also turned off when excessive phase error of the chroma
PLL is present.

If “force color off” is selected, color information is never
present on the outputs.

If “force color on” is selected, color information is present on
the outputs regardless of the color burst amplitude or
chroma PLL phase error.

Y PROCESSING

The black level is subtracted from the luminance data to
remove sync and any blanking pedestal information. Nega­tive values of Y are supported at this point to allow proper
decoding of “below black” luminance levels.

Scaling is done to position black at 8-bit code 0 and white at

.A

H

8-bit code 219.
A chroma trap filter may be used to remove any residual

color subcarrier from the luminance data. The center fre­quency of the chroma trap is automatically determined from
the video standard being decoded. The chroma trap should
be disabled during S-video operation to maintain maximum
luminance bandwidth. Alternately, a 3MHz lowpass filter may
be used to remove high-frequency Y data. This may make a
noisy image more pleasing to the user, although softer.

Coring of the high-frequency Y data may be done to reduce
low-level high frequency noise.

Coring of the Y data may also be done to reduce low-level
noise around black. This forces Y data with the following val­ues to a value of 0:

coring = 1: +/- 1
coring = 2: +/- 1, +/- 2
coring = 3: +/- 1, +/- 2. +/- 3

High-frequency components of the luminance signal may be
“peaked” to control the sharpness of the image. Maximum
gain may be selected to occur at either 2.6MHz or the color
subcarrier frequency. This may be used to make the dis­played image more pleasing to the user. It should not be
used if the output video will be compressed, as the circuit
introduces high-frequency components that will reduce the
compression ratio.

The brightness control adds or subtracts a user-specified
DC offset to the Y data. The contrast control multiplies the Y
data by a user-specified amount. These may be used to
make the displayed image more pleasing to the user.

Finally, a value of 16 is added to generate a nominal range of
16 (black) to 235 (white).

CbCr PROCESSING

The CbCr data is lowpass filtered to either 0.85 or 1.5MHz.
Coring of the CbCr data may be done to reduce low-level

noise around zero. This forces CbCr data with the following
values to a value of 128.

coring = 1: 127, 129
coring = 2: 126, 127, 129, 130
coring = 3: 125, 126, 127, 129, 130, 131

The saturation control multiplies the CbCr data by a user­specified amount. This may be used to make the displayed
image more pleasing to the user. The CbCr data may also
be optionally multiplied by the contrast value to avoid color
shifts when changing contrast.

The hue control provides a user-specified phase offset to the
color subcarrier during decoding. This may be used to cor­rect slight hue errors due to transmission.

YCbCr OUTPUT FORMAT PROCESSING

Y has a nominal range of 16 to 235. Cb and Cr have a nomi­nal range of 16 to 240, with 128 corresponding to zero. Val­ues less than 1 are made 1 and values greater than 254 are

7

HMP8116

made 254.

BLANK is asserted, Y is forced to have a value of 16,

While
with Cb and Cr forced to have a value of 128, unless VBI
data is present.

RGB OUTPUT FORMAT PROCESSING

The 4:2:2 YCbCr data is converted to 4:4:4 YCbCr data and
then converted to either 15-bit or 16-bit gamma-corrected
RGB (R′G′B′) data. While
forced to a value of 0.

15-Bit R′G′B′

The following YCbCr to R′G′B′ equations are used to main­tain the proper black and white levels:

R′ = 0.142(Y - 16) + 0.194(Cr - 128)
G′ = 0.142(Y - 16) - 0.099(Cr - 128) - 0.048(Cb - 128)
B′ = 0.142(Y - 16) + 0.245(Cb - 128)

The resulting 15-bit R′G′B′ data has a range of 0 to 31. Val­ues less than 0 are made 0 and values greater than 31 are
made 31.

The 15-bit R′G′B′ data may be converted to 15-bit linear
RGB, using the following equations. Although the PAL speci­fications specify a gamma of 2.8, a gamma of 2.2 is normally
used. The HMP8116 allows the selection of the gamma to
be either 2.2 or 2.8, independent of the video standard.

for gamma = 2.2:

for R′G′B′ < 0.0812*31

R = (31)((R′/31)/4.5)
G = (31)((G′/31)/4.5)
B = (31)((B′/31)/4.5)

for R′G′B′ >= 0.0812*31

R = (31)(((R′/31) + 0.099)/1.099)
G = (31)(((G′/31) + 0.099)/1.099)
B = (31)(((B′/31) + 0.099)/1.099)

for gamma = 2.8:

R = (31)(R′/31)
G = (31)(G′/31)
B = (31)(B′/31)

16-Bit R′G′B′

The following YCbCr to R′G′B′ equations are used to main­tain the proper black and white levels:

R′ = 0.142(Y - 16) + 0.194(Cr - 128)
G′ = 0.288(Y - 16) - 0.201(Cr - 128) - 0.097(Cb - 128)
B′ = 0.142(Y - 16) + 0.245(Cb - 128)

The resulting 16-bit R′G′B′ data has a range of 0 to 31 for R′
and B′, and a range of 0 to 63 for G′. Values less than 0 are
made 0; R′ and B′ values greater than 31 are made 31, G′
values greater than 63 are made 63.

The 16-bit R′G′B′ data may be converted to 16-bit linear
RGB, using the following equations. Although the PAL speci-

BLANK is asserted, RGB data is

2.2

2.2

2.2

2.8

2.8

2.8

fications specify a gamma of 2.8, a gamma of 2.2 is normally
used. The HMP8116 allows the selection of the gamma to
be either 2.2 or 2.8, independent of the video standard.

for gamma = 2.2:

for R′B′ < 0.0812*31, G′ < 0.0812*63

R = (31)((R′/31)/4.5)
G = (63)((G′/63)/4.5)
B = (31)((B′/31)/4.5)

for R′B′ >= 0.0812*31, G′ >= 0.0812*63

R = (31)(((R′/31) + 0.099)/1.099)
G = (63)(((G′/63) + 0.099)/1.099)
B = (31)(((B′/31) + 0.099)/1.099)

2.2

2.2

2.2

for gamma = 2.8:

R = (31)(R′/31)
G = (63)(G′/63)
B = (31)(B′/31)

2.8

2.8

2.8

BUILT-IN VIDEO GENERATION

When the blue screen, black screen or color bar output is
selected, a full-screen of blue, black or 75% colorbar output
is generated using the currently selected output format. The
type of screen to be generated is determined by bits 2 and 1
of the OUTPUT FORMAT register 02

. When built-in video

H

generation is not desired, the bits need to be set for normal
operation to pass decoded video.

If a video source is input, it will be used to provide the video
timing. If an input video source is not detected, internally­generated video timing will be used.

Pixel Port Timing

The the timing and format of the output data and control sig­nals is presented in the following sections.

HSYNC AND VSYNC TIMING

The HSYNC and VSYNC output timing is VMI v1.4 compati­ble.Figures 4-7 illustrate the video timing. The leading edge of
HSYNC is synchronous to the video input signal and has a
fixed latency due to internal pipeline processing. The pulse
width of the
36

, where the trailing edge of HSYNC has a programmable

H

delay of 0-510 CLK2 cycles from the leading edge.
The leading edge of

way through the first serration pulse of each field. For an odd
field, the trailing edge of
trailing edge of the
pulse. Refer to Figures 4 and 6. For an even field, the trailing
edge of
of the
Figures 5 and 7.

FIELD TIMING

When field information can be determined from the input
video source, the FIELD output pin reflects the video source

HSYNC is defined by the END HSYNC register

VSYNC is asserted approximately half

VSYNC is 5±1 CLK2 cycles after the

HSYNC that follows the last equalization

VSYNC is 5±1 CLK2 cycles leading the leading edge

HSYNC that follows the last equalization pulse. Refer to

8

HMP8116

field state. When field information cannot be determined
from the input video source, the FIELD output pin alternates

NTSC(M)

LINE #

PAL(M)
LINE #

VIDEO
INPUT

HSYNC

VSYNC

FIELD

1

523

‘EVEN’ FIELD

2345678910525524

5245251234567522521

its state at the beginning of each field. FIELD changes state

±1 CLK2 cycles before the the leading edge of VSYNC.

5

‘ODD’ FIELD

NOTE:

3. The trailing edgeofVSYNCis 5±1 clocks after the trailing edgeof HSYNCtobeVMI compatible and to indicate a transitiontoanodd field.

FIGURE 4. NTSC(M) AND PAL(M) HSYNC, VSYNC AND FIELD TIMING DURING AN EVEN TO ODD FIELD TRANSITION

NTSC(M)

LINE #

PAL(M)

LINE #

VIDEO
INPUT

264
261

265 266 267 268 269 270 271 272 273263262
262 263 264 265 266 267 268 269 270260259

HSYNC

VSYNC

FIELD

‘ODD’ FIELD ‘EVEN’ FIELD

NOTE:

4. The trailing edgeof VSYNC is 5±1 clocks after theleading edge of HSYNC tobe VMI compatible and toindicate a transition to anevenfield.

FIGURE 5. NTSC(M) AND PAL(M) HSYNC, VSYNC AND FIELD TIMING DURING AN ODD TO EVEN FIELD TRANSITION

623LINE # 6246251234567622621

VIDEO

INPUT

HSYNC

VSYNC

FIELD

‘EVEN’ FIELD

‘ODD’ FIELD

NOTE:

5. The trailing edgeofVSYNC is 5±1 clocks after the trailing edgeofHSYNC is to be VMIcompatibleandto indicate a transition to anoddfield.

FIGURE 6. PAL(B,D,G,H,I,N,NC) HSYNC, VSYNC AND FIELD TIMING DURING AN EVEN TO ODD FIELD TRANSITION

9

VIDEO
INPUT

HSYNC

VSYNC

HMP8116

311LINE # 312 313 314 315 316 317 318 319 320310309

FIELD

NOTE:

6. The trailing edgeof VSYNC is 5±1 clocks after theleading edge of HSYNC tobe VMI compatible and toindicate a transition to anevenfield.

FIGURE 7. PAL(B,D,G,H,I,N,NC) HSYNC, VSYNC AND FIELD TIMING DURING AN ODD TO EVEN FIELD TRANSITION

BLANK AND DVALID TIMING

DVALID is asserted when P15-P0 contain valid data. The
timing and behavior of
video format and the programmed values for bit 4
(DVLD_DCYC) and bit 5 (DVLD_LTC) of the GENLOCK
CONTROL register 04
format sections that follow for the specific behavior for
DVALID.

BLANK is used to determine if the HMP8116 is generating
active video data.
DVALID to capture digital data from the decoder. BLANK,
DVALID and the video data are output after the internal pipe­line latency and synchronous with the rising edge of CLK2.

VIDEO STANDARD

(MSB/LSB)

DVALID is dependent on the output

. Refer to the specific output video

H

BLANK should be used in conjunction with

ACTIVE

PIXELS/

‘ODD’ FIELD ‘EVEN’ FIELD

During active scan lines

BLANK is negated when the hori­zontal pixel count matches the value in the END H_BLANK
register 32

. A count of 00Hcorresponds to the 50% point of

H

the leading edge of the sync tip after leaving the part.
BLANK is asserted when the horizontal pixel count matches
the value in the START H_BLANK register 31
that horizontally,

BLANK is programmable with two pixel res-

olution.
START V_BLANK register 34

ister 35

determine which scan lines are blanked for each

H

field. During inactivescan lines,
entire scan line. Half-line blanking of the output video cannot
be done. Reference Figure 8 for active video timing and use
Table 2 for typical blanking programming values

TABLE 2. TYPICAL VALUES FOR HBLANK AND VBLANK REGISTERS

LINE

TOTAL

PIXELS/

LINE

LAST

PIXEL

COUNT

START
H_BLANK
(31H/30H)

END

H_BLANK

(32H)

/30H. Note

H

/33Hand END V_BLANK reg-

H

BLANK is asserted during the

START
V_BLANK
(34H/33H)

END

V_BLANK

(35H)

RECTANGULAR PIXELS

NTSC (M), PAL (M)

PAL (B, D, G, H, I,N, NC)

SQUARE PIXELS

NTSC (M), PAL (M)

PAL (B, D, G, H, I,N, NC)

720
720

640
768

858
864

780
944

857 (0359H)
863 (035FH)

779 (030BH)
943 (03AFH)

842 (034AH)
852 (0354H)

758 (02F6H)
922 (039AH)

122 (7AH)
132 (84H)

118 (76H)
154 (9AH)

259 (0103H)
310 (0136H)

259 (0103H)
310 (0136H)

19 (13H)
22 (16H)

19 (13H)
22 (16H)

10

HMP8116

480 ACTIVE
LINES/FRAME
(NTSC, PAL M)

NTSC M PAL B, D, G, H, I, N, N

LINES 1 - 22 NOT ACTIVE

240 ACTIVE LINES

PER FIELD

(LINES 23-262)

LINES 263 - 284 NOT ACTIVE

240 ACTIVE LINES

PER FIELD

(LINES 285 - 524)

LINE 525

NOT ACTIVE

TOTAL PIXELS

ACTIVE PIXELS

ODD FIELD

SYNC AND

PORCH

VERTICAL
BLANKING

EVEN FIELD

FRONT
PORCH

NUMBER OF PIXELS

RECTANGULAR (SQUARE)

NTSC PAL

858
720

(780)
(640)

864
720

BACK

(944)
(768)

LINES 1 - 22 NOT ACTIVE

288 ACTIVE LINES

PER FIELD

(LINES 23 - 310)

LINES 311 - 335 NOT ACTIVE

288 ACTIVE LINES

PER FIELD

(LINES 336 - 623)

LINES 624-625

NOT ACTIVE

TOTAL PIXELS

ACTIVE PIXELS

C

576 ACTIVE

LINES/FRAME

(PAL)

NOTE:

7. The line numbering for PAL (M) followings NTSC (M) line count minus 3 per the video standards.

FIGURE 8. TYPICAL ACTIVE VIDEO REGIONS

TABLE 3. PIXEL OUTPUT FORMATS

PIN NAME 8-BIT, 4:2:2, YCbCr 16-BIT, 4:2:2, YCbCr 15-BIT, RGB, (5,5,5) 16-BIT, RGB, (5,6,5) BT.656

P0
P1
P2
P3
P4
P5
P6
P7

P8
P9

P10
P11
P12
P13
P14
P15

0 [0]
0 [0]
0 [0]
0 [0]
0 [0]
0 [0]
0 [0]
0 [0]

Y0, Cb0, Cr0 [D0]
Y1, Cb1, Cr1 [D1]
Y2, Cb2, Cr2 [D2]
Y3, Cb3, Cr3 [D3]
Y4, Cb4, Cr4 [D4]
Y5, Cb5, Cr5 [D5]
Y6, Cb6, Cr6 [D6]
Y7, Cb7, Cr7 [D7]

Cb0, Cr0 [D0
Cb1, Cr1 [D1
Cb2, Cr2 [D2
Cb3, Cr3 [D3
Cb4, Cr4 [D4
Cb5, Cr5 [D5
Cb6, Cr6 [D6
Cb7, Cr7 [D7

Y0 [D0n]
Y1 [D1n]
Y2 [D2n]
Y3 [D3n]
Y4 [D4n]
Y5 [D5n]
Y6 [D6n]
Y7 [D7n]

n+1
n+1
n+1
n+1
n+1
n+1
n+1
n+1

]
]
]
]
]
]
]
]

B0 [D0
B1 [D1
B2 [D2
B3 [D3
B4 [D4
G0 [D5
G1 [D6
G2 [D7

G3 [D0n]
G4 [D1n]
R0 [D2n]
R1 [D3n]
R2 [D4n]
R3 [D5n]
R4 [D6n]

0 [D7n]

n+1
n+1
n+1
n+1
n+1
n+1
n+1
n+1

]
]
]
]
]
]
]
]

B0 [D0
B1 [D1
B2 [D2
B3 [D3

B4 [D4
G0 [D5
G1 [D6
G2 [D7

G3 [D0n]
G4 [D1n]
G5 [D2n]
R0 [D3n]
R1 [D4n]
R2 [D5n]
R3 [D6n]

n+1
n+1
n+1
n+1
n+1

n+1
n+1
n+1

]
]
]
]
]

]
]
]

0 [0]
0 [0]
0 [0]
0 [0]
0 [0]
0 [0]
0 [0]
0 [0]

YCbCr Data,

Ancillary Data,

SAV and EAV

Sequences
[D0 - D7, where
P8 corresponds

to D0]

R4 [D7n]

NOTE:

8. Definitions in brackets are port definitions duringraw VBI data transfers. Refer to the sectionon teletext for more information on raw VBI.

PIXEL OUTPUT PORT

Pixel data is output via the P0-P15 pins. Refer to Table 3 for
the output pin definition as a function of the output mode.

8-BIT YCbCr OUTPUT

The DVALID output pin may be configured to operate in one
of two ways. The configuration is determined by the
DVLD_LTC bit (bit 4) of the GENLOCK CONTROL register
04

.

H

If DVLD_LTC=0, the
during the entire active video time on active scan lines if CLK2
is exactly 2x the desired output sample rate.

DVALID output is continuously asserted

DVALID being

asserted indicates valid pixel data is present on the P15-P8
pixel outputs.

DVALID is never asserted during the blanking

intervals. Refer to Figure 9.
If DLVD_LTC=1,

DVALID has the same internal timing as the
first mode, but is ANDed with the CLK2 signal, and the result
is output onto the

DVALID pin. This results in a gated CLK2
signal being output during the active video time on active
scan lines. Refer to Figure 10.

If 8-bit YCbCr data is generated, it is output following each
rising edge of CLK2. The YCbCr data is multiplexed as [Cb Y
Cr Y′ CbYCrY′...], with the first active data each scan line
containing Cb data. The pixel output timing is shown in Fig-

11

HMP8116

ures 9 and 10.
BLANK, HSYNC, VSYNC, DVALID, VBIVALID, and FIELD

are output following the rising edge of CLK2. When

CLK

DVALID

BLANK

P[15-8]

NOTE:

t

DVLD

Cb

Y

0

0

BLANK

Cr

0

is asserted and
have a value of 16 for Y and 128 for Cb and Cr .

Y

Cb

1

2

VBIVALID is deasserted, the YCbCr outputs

Y

2

Cr

Y

2

3

Cb

Y

4

4

9. Y0is the first active luminance pixel data of a line. Cb0and Cr0are first active chrominance pixel data in a line. Cb and Cr will alternate
every cycle due to the 4:2:2 subsampling. Pixel data is not output during the blanking period, but the values on the ports are forced to
blanking levels.

FIGURE 9. OUTPUT TIMING FOR 8-BIT YCbCr MODE (DVLD_LTC = 0)

CLK

DVALID

BLANK

P[15-8]

NOTES:

t

DVLD

Cb

Y

0

0

Cr

Y

0

Cb

1

Y

2

2

Cr

Y

2

Cb

3

Y

4

4

10. Y0is the first active luminance pixel data of a line. Cb0and Cr0are first active chrominance pixel data in a line. Cb and Cr will alternate
every cycle due to the 4:2:2 subsampling. Pixel data is not output during the blanking period, but the values on the ports are forced to
blanking levels.

11. When DVLD_LTCis set to 1, the polarity ofDVALIDneeds to be set to active low,otherwise DVALID will stay lowduring active video and
be gated with the clock only during the blanking interval.

FIGURE 10. OUTPUT TIMING FOR 8-BIT YCbCr MODE (DVLD_LTC = 1)

16-BIT YCbCr, 15-BIT RGB, OR 16-RGB OUTPUT

In these output modes, DVALID may be configured to oper­ate in one of four modes as controlled by the DVLD_LTC and
DVLD_DCYC bits of the GENLOCK CONTROL register
(04

). Bit 4 is the DVLD_LTC bit and bit 5 is the

H

DVLD_DCYC bit.
If DVLD_LTC=0 and DVLD_DCYC=0 ,

only during the active video time on active scan lines. Thus,
DVALID being asserted indicates valid pixel data is present
on the P0-P15 pixel outputs.

DVALID is never asserted dur­ing the blanking intervals. In this mode
50% duty cycle only during the active video times. The tim­ing diagrams for this mode can be found in figures 11 and

12.

DVALID is present

DVALID will have a

same as the first mode, with the exception that
not have a 50% duty cycle. This mode is intended for back­ward compatibility with HMP8112(A) timing dependancies in
which

DVALID did not have a 50% duty cycle timing and
other timing variations. The timing diagrams for this mode
can be found in figures 13 and 14.

If DVLD_LTC=1 and DVLD_DCYC=0,
entire line time on all scan lines.

DVALID is present the

DVALID may occasionally
be negated for two consecutive CLK2 cycles just prior to
active video. In this mode

DVALID is guaranteed havea 50%
duty cycle only during the active video times. The timing for
this mode differs from the timing shown in figures 11 and 12
only in that

DVALID will also be asserted during the blanking

portion of the video line time as described above.

DVALID does

If DVLD_LTC=0 and DVLD_DCYC=1,

DVALID behaves the

12

HMP8116

If DVLD_LTC=1 and DVLD_DCYC=1,
during the entire line time on all scan lines.

DVALID is present

DVALID is
asserted during the blankingintervals as needed to ensure a
constant number of total samples per line. The timing for this
mode differs from the timing shown in figures 13 and 14 only
in that

DVALID will also be asserted during the blanking por-

tion of the video line time as described above.
If 16-bit YCbCr, 15-bit RGB data, or 16-bit RGB data is gen-

erated, it is output following the rising edge of CLK2 while

CLK

DVALID

BLANK

Cb

Y

0

0

Y

1

Cr

0

P15-P8

P7-P0

DVALID is asserted. Either linear or gamma-corrected RGB
data may be output. The pixel output timing is shown in Fig­ures 11 to 14.

BLANK, HSYNC, VSYNC, DVALID, VBIVALID, and FIELD
are output following the rising edge of CLK2. When
is asserted and

VBIVALID is deasserted, the YCbCr outputs

BLANK

havea value of 16 forY and 128 for Cb and Cr; the RGB out­puts have a value of 0.

Cb

Y

2

2

Y

3

Cr

2

Cb

Y

4

4

t

DVLD

NOTES:

12. Y0is the first active luminance pixel data of a line. Cb0and Cr0are first active chrominance pixel data in a line. Cb and Cr will alternate

every cycle due to the 4:2:2 subsampling.

13. BLANK is asserted per Figure 8.

FIGURE 11. OUTPUT TIMING FOR 16-BIT YCbCr MODE (DVLD_LTC = 0, DVLD_DCYC = 0)

CLK

DVALID

P15-P11

[P14-P10]

P10-P5

[P9-P5]

P4-P0

R

0

G

0

B

0

R

1

G

1

B

1

R

2

G

2

B

2

R

3

G

3

B

3

R

4

G

4

B

4

t

NOTE:

BLANK is asserted per Figure 8.

14.

DVLD

FIGURE 12. OUTPUT TIMING FOR 16-BIT [15-BIT] RGB MODE (DVLD_LTC = 0, DVLD_DCYC = 0)

13