WT6116 View Datasheet(PDF) - Weltrend Semiconductor
Part Name
Description
Manufacturer
WT6116 Datasheet PDF : 39 Pages
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WT6132/WT6124/WT6116
Data Sheet Rev. 1.01
Horizontal frequency counter
A 12-bit counter is used to measure horizontal frequency. User can choose 16ms or 32ms time interval
to count pulse number of Hsync every 16.384ms or 32.768ms. For example, if QUICK bit is set, when a
16.384ms time frame begins, it resets the counter and starts counting Hsync pulses till 16ms reached,
then loads the counter value to HFREQ_H and HFREQ_L registers. If the H frequency is over 125KHz,
the H counter will stop counting and set overflow flag (HOVF ) to “1”.
The sync processor interrupt is generated every 16.384ms or 32.768ms for checking H frequency. This
interrupt will be cleared after reading the HFREQ_H register.
Hsync
Hfreq Counter
Enable
Hfreq Counter
Clock
Interrupt
16/32 ms
16.384/32.768
Fig.5 Horizontal Frequency Counter timing
Horizontal Frequency Register
Name Addr R/W Initial Bit 7
HFREQ_L 0008h R xxh HLVL
HFREQ_H 0009h R xxh HOVF
Bit 6
HINPOL
HFH6
Bit 5
--
HFH5
Bit4
HFL4
HFH4
Bit 3
HFL3
HFH3
Bit 2
HFL2
HFH2
Bit 1
HFL1
HFH1
Bit 0
HFL0
HFH0
Bit Name
Description
HLVL
“1” : Indicates Hsync pin is high level.
“0” : Indicates Hsync pin is low level.
HINPOL “1” : Indicates Hsync input is positive polarity.
“0” : Indicates Hsync input is negative polarity.
HOVF Indicates H counter is overflowed (over 125KHz) when this bit is set.
HFH6 …HFH0 Indicates the Hsync frequency in kHz.
HFL4 … HFL0 When QUICK=”0”, HFL4 ~ HFL0 indicates the Hsync frequency in 31.25Hz unit.
When QUICK=”1”, HFL4 ~ HFL1 indicates the Hsync frequency in 62.5Hz.
Example of Hsync Frequency Calculation
QUICK=”1”
HFH6..0 HFL4..0 Max. Freq Min. Freq
$40h $00000b 64.0313KHz 63.9687KHz
$40h $00001b 64.0625KHz 64.0000KHz
$40h $00010b 64.0938KHz 64.0312KHz
$40h $00011b 64.1250KHz 64.0625KHz
$51h $10000b 81.5313KHz 81.4687KHz
$51h $10001b 81.5625KHz 81.5000KHz
$51h $10010b 81.5938KHz 81.5312KHz
$51h $10011b 81.6250KHz 81.5625KHz
HFH6..0
$40h
$40h
$51h
$51h
QUICK=”0”
HFL4..0 Max. Freq Min. Freq
$0000xb 64.0625KHz 63.9375KHz
$0001xb 64.1250KHz 64.0000KHz
$1000xb 81.5625KHz 81.4375KHz
$1001xb 81.6250KHz 81.5000KHz
Weltrend Semiconductor, Inc.
Page 10
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