TA1383AFG Datasheet, PDF (13/47 Pages) Toshiba Semiconductor – NTSC Chroma Decoder, Multi-Point Scan Sync Processor, H/V Frequency Counter IC for Color TV

TA1383AFG
Signal
Function
Detects vertical skew of VCR.
V-SKEW
0: no skew 1: skew
V-SKEW is detected only when NTSC signal is input.
Detects 2-/3-level sync of D-SYNC2 IN (pin 6).
C-SYNC
0: 2-level sync 1: 3-level sync
Detects sync width per 1H.
Note: If 525I/P 60-Hz signal has half SYNC width or less, 3-level sync may be determined.
Counts vertical frequency of signal selected by FREQ DET SW.
0000000 to 0011100: No VD
0011101: Vicinity of 195 Hz
1111111: Vicinity of 44.6 Hz
How to calculate vertical frequency (X);
V FREQUENCY DET
Converts data read from V-FREQ DET into decimal value and calls value Y. Z = 176.54 µs.
Vertical frequency (X) = 1 ÷ (Y × Z) [Hz]
Vertical frequency error is Y = −1 to +1. When vertical frequency is 195 Hz or more, frequency cannot be
counted accurately. Note that time constant used to integrate C.SYNC then separate V-SYNC is 9 µs
(error ±1 µs).
Data read first time after power on are undefined.
Counts horizontal frequency of signal selected by FREQ DET SW.
00000000: Quiescent 11111111: 120 kHz or more
How to calculate horizontal frequency (X);
X, Y, and Z are defined the same as those for vertical frequency.
H FREQUENCY DET
Horizontal frequency (X) = Y ÷ (12 × Z) [kHz]
Horizontal frequency error is Y = −1 to +2. When horizontal frequency is 120 kHz or more, frequency
cannot be counted accurately. When horizontal frequency is approx. 142 kHz to approx. 200 kHz, data are
read as 00000000 by the timing of counting.
When V-SYNC or VD is not input, horizontal frequency cannot be counted. Data are read as 00000000.
Data read first time after power on are undefined.
Note 1:
Note 2:
To count horizontal or vertical frequency, data are read between the first V-SYNC/VD and the second
V-SYNC/VD following the reset pulse generated at the second byte as the start trigger. To stabilize data, set
the bus read interval to 3 V or longer. Discard the data read the first time because they are undefined.
However the frequency is counted when BUS is read at Read Mode 1. Therefore the data that is BUS read
at Read Mode 2 is valid.
Even when Read Mode 1 is switched to Read Mode 2, set the BUS read interval to 3 V or longer.
Figures of BUS read interval at Read Mode 2
Data 1 and
Data 2 and
Read Timing
Start trigger 1
Start trigger 2
Start trigger 3
More than 3 V
V-SYNC or VD
Counting period 1
(to data 1)
Counting period 2
(to data 2)
Figures of BUS read interval at Read Mode 2
Note 3: Though there is no restriction for setting BUS read interval at Read Mode 1, set the interval to 1 V per one
period at shortest to read the data accurately.
Decision algorithm (detection range, detection times and so on) for H/V frequency detection should be
determined under consideration of forward Notes and the other factors such as signal strength, existence of
ghost signal, APC stability, I²C BUS data transmission and so on via prototype TV set evaluation.
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2005-09-05