SDA9400 Datasheet, PDF (34/94 Pages) Micronas – Scan Rate Converter using Embedded DRAM Technology Units

SDA 9400
Block diagram of global motion, movie mode and phase detection
GMTHL GMTHU GMAS GMAM
muxout
SHYST
Counter
COUNTGM _Hysteresis
spatial
Hysteresis
time
GMOTION
FID3
COUNTMOV
Counter
MOVIE
MODE AND
PHASE
DETECTION
MMTHL
MMTC
MOVPHINV THYON
RESMOV AMMON
MOVMO
MOVPH
The muxout and FID3 values (Field difference 1, see also Motion detection for scan rate conversion
on page 29) are accumulated during each incoming field. After accumulation the value COUNTGM
is compared with a threshold TH. It is assumed, that the whole picture is moving, if the accumulated
value is greater than the threshold (SHYST=1). Otherwise it will be assumed, that the picture is still
(SHYST=0). The threshold TH itself depends on the actual GMOTION value. This is a kind of spatial
hysteresis. If the actual GMOTION value is zero, then TH is equal GMTHU. In the other case that
GMOTION is one, TH is equal GMTHL.
Behaviour spatial hysteresis
SHYST
1
0
COUNT >= TH
COUNT < TH
TH
64 * GMTHU
64 * GMTHL
GMOTION
0
1
The time hysteresis block generates the final GMOTION value. The GMOTION value will only
changed, if at least the last GMAM/GMAS fields had the same SHYST value.
Behaviour of time hysteresis
GMOTION(T)
0
last GMAS fields, SHYST were 0
Micronas
34
Preliminary Data Sheet