Rev. 1.0, 02/00, page 556 of 1141
26.1.2
Block Diagram
Figure 26.1 shows a block diagram of the servo circuits.
4-head
special
playback
controller
- +
SV1(P30)
EXCAP(P81)
( )
SV2(P31)
( )
EXCTL(P82)
)
+
+
+
+
+
- +
- +
-
CTL
Head
CTL Amp
CTL
Head
CFG
CAP
PWM
DRM
PWM
DFG
DPG(P87)
VIDEOFF
AUDIOFF
Vpulse
H.Amp SW(P84)
C.ROTARY(P83)
COMP(P85)
Csync
EXTTRG(P86)
OSCH
REC:ON
ADTRIG
(HSW)
Ep
PWM
Es
Es
Ep
REC
REC
PB.ASM
CTLFB
PB.CTL
PB.
ASM
(NTSC)
DVCTL
Gain control
by register
setting
REF30,REF30X,CREF,
CTLMONI,DVCFG,
DFG,DPG,DFG,etc
Internal signal
monitor controller
(PAL)
REF30X
REC-CTL
DutyI/O
(Duty deter-
minator)
(Assemble
recording)
DVCFG
DVCFG2
Gain up.
XE:ON
VD
RP0 to 7/
(P60 to 67,
P74 to 77)
Sync
separator
REC-CTL
generator
VISS
circuit
Noise
Det.
A/D
converter
Timer X1
Timer L
Timer R
AN pins
PWM
X-value
adjustment
Gain up.
RP0 to 7/
(P60 to 67,
P74 to 77)
PPG0 to 7/
(P70 to 77)
PPG0 to 7/
(P70 to 77)
REF30P(PB:30Hz,REC:1/2VD)
CREF
Res
System
clock
Additional
V pulse
generator
Head-switch
timing
generator
Drum system
reference
signal
Capstan
system
reference
signal
Phase
error
detector
Phase
error
detector
Digital
filter
Digital
filter
Digital
filter
Digital
filter
Frequency
divider
Frequency
divider
Speed
error
detector
Speed
error
detector
Figure 26.1 Block Diagram of Servo Circuits