AD9888
Table V. Control Register Map (continued)
Register Name Function
Read and
Write or
Address Read Only Bits Value
Hex
Default
14H
RO
7:0
Sync Detect
Bit 7—Hsync Detect. It is set to Logic 1 if Hsync is present on the analog
interface, else it is set to Logic 0.
Bit 6—AHS: Active Hsync. This bit indicates which analog Hsync is being
used. (Logic 0 = Hsync input pin, Logic 1 = Hsync from sync-on-green.)
Bit 5—Input Hsync Polarity Detect. (Logic 0 = active low, Logic 1 = active
high.)
Bit 4—Vsync detect. It is set to Logic 1 if Vsync is present on the analog
interface, else it is set to Logic 0.
Bit 3—AVS: Active Vsync. This bit indicates which analog Vsync is being
used. (Logic 0 = Vsync input pin, Logic 1 = Vsync from sync separator.)
Bit 2—Output Vsync Polarity Detect. (Logic 0 = active high, Logic 1 =
active low.)
Bit 1—Sync-on-Green Detect. It is set to Logic 1 if sync is present on the
green video input, else it is set to 0.
Bit 0—Input COAST Polarity Detect. (Logic 0 = active low, Logic 1 =
active high.)
15H
R/W
7:0
1*******
*1******
**0*****
Bit 7—Channel Mode. Determines single-channel or dual-channel output
mode. (Logic 0 = single-channel mode, Logic 1 = dual-channel mode.)
Bit 6—Output Mode. Determine interleaved or parallel output mode.
(Logic 0 = interleaved mode, Logic 1 = parallel mode.)
Bit 5—A/B Invert. Determines which port outputs the first data byte after
Hsync. (Logic 0 = A port, Logic 1 = B port.)
***0****
****0***
*****11*
*******0
Bit 4—4:2:2 Output Formatting Mode.
Bit 3—Input Mux Control.
Bits [2:1]—Input Bandwidth.
Bit 0—External Clock. Shuts down PLL and allows external clock to drive the
part. (Logic 0 = use internal PLL, Logic 1 = bypassing of the internal PLL.)
16H
17H
18H
19H
R/W
R/W
RO
7:0
7:3
7:0
7:0
11111111 Test Register
00000000 Test Register
Test Register
Must be set to 11111110 for proper operation.
Must be set to default for proper operation.
RO
Test Register
*The AD9888 only updates the PLL divide ratio when the LSBs are written to (Register 02H).
REV. B
–19–
ROCHESTER [ Rochester Electronics ]
