MTV112E View Datasheet(PDF) - Myson Century Inc
Part Name
Description
Manufacturer
MTV112E Datasheet PDF : 19 Pages
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MYSON
TECHNOLOGY
MTV112E
(Rev 1.8)
DA11 (r/w) : The output pulse width control for DA11.
DA12 (r/w) : The output pulse width control for DA12.
DA13 (r/w) : The output pulse width control for DA13.
WDT (w) :
Watchdog timer & special control bit.
DIV253 = 1 → The PWM DAC output frequency is Xtal frequency/253.
= 0 → The PWM DAC output frequency is Xtal frequency/256.
*1. All D/A converters are centered with value 80h after power-on.
4. H/V SYNC Processing
The H/V SYNC processing block performs the functions of composite signal separation, SYNC input
presence check, frequency counting, and polarity detection and control, as well as the protection of VBLANK
output while VSYNC speeds up to a high DDC communication clock rate. The present and frequency
function block treat any pulse less than one OSC period as noise.
4.1 Composite SYNC Separation
MTV112E continuously monitors the input HSYNC. If the vertical SYNC pulse can be extracted from the
input, a CVpre flag is set and the user can select the extracted "CVSYNC" for the source of polarity check,
frequency count and VBLANK. The CVSYNC will have a 10-16 us delay compared to the original signal. The
delay depends on the OSC frequency and composite mix method.
4.2 H/V Frequency Counter
MTV112E can discriminate HSYNC/VSYNC frequency and saves the information in XFRs. The 15-bit
Hcounter counts the time of the 64xHSYNC period, but only 11 upper bits are loaded into the
HCNTH/HCNTL latch. The 11-bit output value is {2/H-Freq} / {1/OSC-Freq}, updated once per
VSYNC/CVSYNC period when VSYNC/CVSYNC is present or continuously updated when VSYNC/CVSYNC
is not present. The 14-bit Vcounter counts the time between 2 VSYNC pulses, but only 9 upper bits are
loaded into the VCNTH/VCNTL latch. The 9-bit output value is {1/V-Freq} / {512/OSC-Freq}, updated every
VSYNC/CVSYNC period. An extra overflow bit indicates the condition of the H/V counter overflow. The
VFchg/HFchg interrupt is active when VCNT/HCNT value changes or overflows. Tables 4.2.1 and 4.2.2
show the HCNT/VCNT value under the operations of 8MHz and 12MHz.
MTV112E Revision 1.8 05/18/2001
6/19
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