ML6430 Просмотр технического описания (PDF) - Micro Linear Corporation

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ML6430

Genlocking Sync Generator with Digital Audio Clock for NTSC, PAL & VGA

Micro Linear Corporation 

ML6430/ML6431

FUNCTIONAL DESCRIPTION (Continued)

CONTROL REGISTER INFORMATION

REGISTER

PulsePol[2:0]

Clk4X

Pixel[10:0]

Burst

CSyncRaw

RawClamp

TTL Sync

WideBlank

HDelay[6:0]

Noise Gating

Test 3,1,4

External 54

Clock IN

FAud[1:0]

VCR

SLEEP

Thresh[1:0]

VGA

Div4

Fstd[2:0]

PALXTAL

SETTING

000

0

Determined by PRESET pin

0

0

0

0

0

1000000

0

0, 0, 0

0

01

0

0

11

Determined by PRESET pin

Determined by PRESET pin

Determined by PRESET pin

Determined by PRESET pin

Table 8. Default Control Register Settings for Preset Mode

REGISTER DESCRIPTION

SLEEP: Enables or disables sleep mode. When using

serial bus control, ALL registers must be programmed to

their intended state after power up to ensure correct

operation of the ML6430/ML6431.

CSR: Composite sync register bit controls whether

composite sync output is from the sync separator,

(raw CSYNC) or from the internal pulse generator

(regenerated CSYNC).

Pulse Polarity Control: The active state of output sync

pulses, blanking pulses, or clamp pulses may be

programmed to either 0 or 1 state by use of these bits.

P0: CSYNC pulse output is high active when 1,

low active when 0.

P1: HBLANK, and VBLANK pulse outputs are high

active when 1, low active when 0.

P2: SCLAMP and BCLAMP pulse outputs are high

active when 1, low active when 0.

Burst: Controls the length of Burst Gate so pulse can be

used for either burst gating in encoder applications or

back porch clamping.

RawClamp: Controls the source of the SCLAMP (sync

clamp) pulse. Pulse is timed relative to incoming sync

edge, or regenerated sync edge.

PALXTAL: Controls the expected crystal frequency at the

oscillator inputs. 0 = NTSC 3.58MHz, or 1 = PAL 4.43MHz.

Thresh1,Thresh0: Selects the pixel error threshold at

which relock is initiated. Values are:

0,0: 2.5 pixels

0,1: 2.5 pixels

1,0: 1.0 pixels

1,1: 4.0 pixels

Noise Gating: Enables a 3/4 line window to lockout any

unwanted horizontal sync pulses.

VGA: Produces non-interlaced progressive scan outputs.

Div4: Controls the prescaler in the M/N loop. High means

that 4Fs external oscillator signals are expected, low

assumes a PAL or NTSC Fs crystal will be used.

VCR: Controls the gain range and locking maneuvers of

the digital loop. Provides better locking to the

unpredictability of VCR headswitches and jitter.

Blanking Width Control: The number of blanked lines in

the vertical interval is programmable to either 9 or 16.

XTAL: external Crystal Control: 0=NTSC 3.58MHz, or

1=PAL 4.43MHz, for both local crystal and external

oscillator mode.

External 54MHz Clock: This mode permits injecting a

54MHz clock (or other 4X clock) directly into the

horizontal pixel counter via the SLEEP pin. All timing

pulses are synchronous to the 54MHz clock (or other 4X

clock).

Serial Bus Control: To place the Ml6430/ML6431 in serial

mode, take P0 (Preset ) to logical '0' or ground. The serial

control system is written to by the external processor in 8-

bit bytes. Each of these bytes is partitioned into an

address (upper 4 bits of serial byte) and a data register

(lower 4 bits of serial byte). In Table 10, the Register

heading refers to the 4-bit address, and Data Bit refers to a

particular bit in the 4-bit register (Bit0 is LSB).

Pixel: Program all bits to zero to enable default values for

each standard. Otherwise use the following equation:

P[10:0] = 2 ´ (number of pixels per line) – 1024 (1)

Test: All test bits must be programmed to zero.

16

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