參數(shù)資料
型號(hào)： SAA7371
廠商： NXP Semiconductors N.V.
英文描述： Digital servo processor and Compact Disc decoder CD7
中文描述： 數(shù)字伺服處理器和CD7抗原光盤解碼器
文件頁數(shù)： 28/60頁
文件大?。?/td> 247K
代理商： SAA7371
1998 Jul 06
28
Philips Semiconductors
Product specification
Digital servo processor and
Compact Disc decoder (CD7)
SAA7371
7.14.6
D
EFECT DETECTION
Fig.20 Block diagram of defect detector.
handbook, full pagewidth
DECIMATION
FILTER
FAST
FILTER
DEFECT
GENERATION
PROGRAMMABLE
HOLD-OFF
SLOW
FILTER
defect
output
sat1
sat2
+
MBG421
A defect detection circuit is incorporated into the
SAA7371. If a defect is detected, the radial and focus error
signals may be zeroed, resulting in better playability.
The defect detector can be switched off, applied only to
focus control or applied to both focus and radial controls
under software control (part of foc_parm1).
The defect detector (see Fig.20) has programmable set
points selectable by the parameter defect_parm.
7.14.7
O
FF
-
TRACK DETECTION
During active radial tracking, off-track detection has been
realised by continuously monitoring the off-track counter
value. The off-track flag becomes valid whenever the
off-track counter value is not equal to zero. Depending on
the type of extended S-curve, the off-track counter is reset
after 0.75 extend or at the original track in the 2.25 track
extend mode.
7.14.8
H
I
-
LEVEL FEATURES
7.14.8.1
Interrupt mechanism and STATUS pin
The STATUS pin is an output which is active LOW, its
output is selected by register 7 to be either the status bit
(active LOW) selected by register 2 (only available in
4-wire bus mode) or the interrupt signal generated by the
servo part.
8 signals from the interrupt status register are selectable
from the servo part via the interrupt_mask parameter.
The interrupt is reset by sending the read hi-level status
command. The 8 signals are as follows;
1.
Focus lost: drop out of longer than 3 ms.
2.
Subcode ready.
3.
Subcode absolute seconds changed.
4.
Subcode discontinuity detected: new subcode time
before previous subcode time, or more than 10 frames
later than previous subcode time.
5.
Radial error: during radial on-track, no new subcode
frame occurs within time defined by playwatchtime
parameter. During radial jump, less than 4 tracks have
been crossed during time defined by jumpwatchtime
parameter.
Autosequencer state change.
Autosequencer error.
Subcode interface blocked: the internal decoder
interface is being used.
6.
7.
8.
It should be noted that if the STATUS pin output is selected
via register 2 and either the microcontroller writes a
different value to register 2 or the decoder interface is
enabled then the STATUS output will change.
7.14.8.2
Decoder interface
The decoder interface allows registers 0 to F to be
programmed and subcode Q-channel data to be read via
servo commands. The interface is enabled/disabled by the
preset latch command (and the xtra_preset parameter).
7.14.8.3
Automatic error handling
Three watchdogs are present:
1.
Focus: detects focus drop out of longer than 3 ms, sets
focus lost interrupt, switches off radial and sledge
servos, disables drive to disc motor.
2.
Radial play: started when radial servo is on-track
mode and a first subcode frame is found. Detects
when maximum time between two subcode frames
exceeds time set by playwatchtime parameter; then
sets radial error interrupt, switches radial and sledge
servos off, puts disc motor in jump mode.
3.
Radial jump: active when radial servo in long jump or
short jump modes. Detects when the off-track counter
value decreases by less than 4 tracks between two
readings (time interval set by jumpwatchtime
parameter); then sets radial jump error, switches radial
and sledge servos off to cancel jump.
The focus watchdog is always active, the radial watchdogs
are selectable via the radcontrol parameter.
相關(guān)PDF資料
PDF描述
SAA7371GP Digital servo processor and Compact Disc decoder CD7
SAA7372 Digital servo processor and Compact Disc decoder CD7
SAA7373 Digital servo processor and Compact Disc decoder CD7
SAA7373GP Digital servo processor and Compact Disc decoder CD7
SAA7374 Low voltage digital servo processor and Compact Disc decoder CD7LV
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
SAA7371GP 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Digital servo processor and Compact Disc decoder CD7
SAA7372 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Digital servo processor and Compact Disc decoder CD7
SAA7373 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Digital servo processor and Compact Disc decoder CD7
SAA7373GP 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Digital servo processor and Compact Disc decoder CD7
SAA7374 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Low voltage digital servo processor and Compact Disc decoder CD7LV
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。

采購需求

(若只采購一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購

我的聯(lián)系方式

*
*
*