Rev. 1.0, 02/00, page 567 of 1141
φ
s = fosc/2
φ
s/2
φ
s/4
Dummy read
External
frequency
signal
(EXTTRG)
Field
detection
signal
W
W
R/W
W
W
WW
PB
→
REC
PB
↑
,
↓
ASM
REC/PB
V noise detection signal
REF30
REF30P
Video FF
VD
Match
Mask
Clear
W
R/W
W
Internal bus
R/W
Internal bus
Toggle
RCS
REF30 counter register (16 bits)
OD/EV
VST
FDS
VEG
Edge
detec-
tion
↑
Edge
detec-
tion
VNA
CVS
REX
TBC
Reference period buffer 1 (16 bits)
Reference period register 1 (16 bits)
Comparator (16 bits)
Counter (16 bits)
Figure 26.6 REF30 Signal Generator