TMC22x5yA
PRODUCT SPECIFICATION
XFEN
YERR
2:1
MUX
K[4:0]
X[7:0]
XLUT
Input
Select
XLUT
PERR
MERR
Filter
65-22x5y-61
XIP[1:0]
Figure 20. XLUT Input Selection
For PAL comb filters the LYE, LME, and LPE errors signals
are always selected by default. In this way the error signals
into the XLUT always represent the comb filter being imple-
mented. The resolution of the error signals selected is con-
trolled by the XIP[1:0] register bits as shown in Table 6:
XLUT Input Selection. The position of these error signals on
the XLUT input address X[7:0] is also shown.
Table 7. XLUT Output Function. (cont.)
XLUT
OUTPUT
K
16
:
16 - 50% Bandsplit, 50% Comb
:
29
30
31
29
Table 6. XLUT Input Selection
30
XIP[1:0]
Function
32 - 100% Comb
00
2 bits of phase error (X[7:6]), 3 bits of
chroma (X[5:3]) and luma magnitude error
(X[3:0]).
The special function assigned to K = 0 is programmed into
the XSF[1:0] register bits, as shown in Table 8.
01
10
4 bits of chroma (X[7:4]) and luma
magnitude error (X[3:0]).
Table 8. XLUT Special Function Definitions
KIP
1-0
XLUT special function selection
3 bits of phase error (X[7:5]), 3 bits of
chroma magnitude error (X[4:2]), and 2
bits of luma magnitude error (X[1:0]).
Y
C
00
comb
simple
comb
simple
comb
11
4 bits of phase error (X[7:4]) and chroma
magnitude error (X[3:0]).
01
10
11
simple
flat with notch
flat with notch
The selected comb fail signals are translated by the user-
programmed configuration within the 256*5 XLUT into the
mix signal (K) which controls the 30 levels of cross-fade
between the weighted comb filter and the band split filters.
The 1 to 31 mix signal is modified on the input to the cross-
fade to produce a 0 to 32 control signal, as shown in Table 7.
The “Flat with notch” selection passes the FLAT input
through onto the luminance channel and selects the notch
filter, centered at 0.25 of the normalized clock frequency.
This mode is therefore only useful with inputs at 4*Fsc or in
cases when a notch at 0.25 of the normalized clock
frequency is adequate for application.
Table 7. XLUT Output Function.
XLUT
The XLUT output, is fed through a bypassable low-pass
filter KLPF to avoid switching between comb and simple
decoders on a pixel by pixel basis. When the special function
is selected (K = 0) the input to the KLPF is held and the filter
is automatically bypassed. The output of the XLUT can be
externally monitored by reading XOP[4:0] in register 4Bh.
OUTPUT
K
0
Special function (e.g. luma comb and HPF
on chroma)
1
2
3
:
0 - 100% Bandsplit
2
3
:
52
REV. 1.0.0 2/4/03
CADEKA [ CADEKA MICROCIRCUITS LLC. ]
