Datasheet

AD9984A
Rev. 0 | Page 25 of 44
Hex
Address
Read/Write,
Read Only Bits
Default
Value Register Name Description
6 *0** ****
Hsync Source Select. Determines the source of the Hsync for PLL and
sync processing. This bit is used only if Reg. 0x12, Bit 7 is set to 1 or if
both syncs are active.
0 = Hsync is from HSYNCx input pin.
1 = Hsync is from SOG.
5 **0* ****
Hsync Input Polarity Override.
0 = The chip selects the Hsync input polarity.
1 = The input polarity of Hsync is controlled by Reg. 0x12, Bit 4.
4 ***1 ****
Hsync Input Polarity. This bit is used only if Reg. 0x12, Bit 5 is set to 1.
0 = Hsync input polarity is negative.
1 = Hsync input polarity is positive.
3 **** 1***
Hsync Output Polarity. Sets the polarity of the Hsync output signal
(HSOUT).
0 = HSOUT polarity is negative.
1 = HSOUT polarity is positive.
0x13
R/
W
7:0 0010 0000 Hsync Duration Sets the number of pixel clocks that HSOUT is active.
0x14
R/
W
7 0*** **** Vsync Control
Vsync Source Override.
0 = The chip determines the active Vsync source.
1 = The active Vsync source is set by Reg. 0x14, Bit 6.
6 *0** ****
Vsync Source Select. Determines the source of Vsync for sync
processing. This bit is used only if Reg. 0x14, Bit 7 is set to 1.
0 = Vsync is from the VSYNCx input pin.
1 = Vsync is from the sync separator.
5 **0* ****
Vsync Input Polarity Override.
0 = The chip selects Vsync input polarity.
1 = The input polarity of Vsync is set by Reg. 0x14, Bit 4.
4 ***1 ****
Vsync Input Polarity. This bit is used only if Reg. 0x14, Bit 5 is set to 1.
0 = Vsync input polarity is negative.
1 = Vsync input polarity is positive.
3 **** 1***
Vsync Output Polarity. Sets the polarity of the output Vsync signal
(VSOUT).
0 = VSOUT polarity is negative.
1 = VSOUT polarity is positive.
2 **** *0**
Vsync Filter Enable. This needs to be enabled when using the Hsync
to Vsync counter.
0 = The Vsync filter is disabled.
1 = The Vsync filter is enabled.
1 **** **0*
Vsync Duration Block Enable. This is designed to be used with the
Vsync filter.
0 = Vsync output duration is unchanged.
1 = Vsync output duration is set by Register 0x15.
0x15
R/
W
7:0 0000 1010 Vsync Duration
Sets the number of Hsyncs that Vsync out is active. This is only used if
Reg. 0x14, Bit 1 is set to 1.
0x16
R/
W
7:0 0000 0000 Precoast The number of Hsync periods to coast prior to Vsync.
0x17
R/
W
7:0 0000 0000 Postcoast The number of Hsync periods to coast after Vsync.
0x18
R/
W
7 0*** ****
Coast and Clamp
Control
Coast Source. Determines the source of the coast signal.
0 = Using internal coast generated from Vsync.
1 = Using external coast signal from COAST pin.
6 *0** ****
Coast Polarity Override.
0 = The chip selects the coast polarity.
1 = The polarity of the coast signal is set by Reg. 0x18, Bit 5.
5 **1* ****
Coast Polarity. This bit is used only if Reg. 0x18, Bit 6 is set to 1.
0 = Coast polarity is negative.
1 = Coast polarity is positive.
4 ***0 ****
Clamp Source Select. Determines the source of the clamp timing.
0 = Uses the internal clamp generated from Hsync.
1 = Uses the external CLAMP signal.