AD9910 Analog Devices, AD9910 Datasheet - Page 13

• Manufacturer Part Number: AD9910
• Description: 3.3V CMOS Direct Digital Synthesizer
• Manufacturer: Analog Devices

PRELIMINARY TECHNICAL DATA
quency parameter, thereby increasing its affect on the DDS fre-
quency by a factor of 2. The FM Gain word effectively controls
Destination
Bits <1:0>
00
01
10
11
Data Word Parti-
tioning <17:2>
<17:10>
<17:4>
<17:2>
<17:2>
<9:2>
14-bit amplitude parame-
ter (unsigned integer)
16-bit phase parameter
(unsigned integer)
32-bit frequency parame-
ter (unsigned integer)
8 bits amplitude (un-
signed integer)
8 bits phase (unsigned
integer)
DDS Signal Control
Parameter
Figure 7: Parallel data port modulation mode
Table 2: Parallel port destination bits
Rev. PrD| Page 13 of 13
Amplitude scales from 0 to 1-2
<3:0> are ignored.
Phase offset ranges from 0 to 2π(1-2
The alignment of 16-bit data word with the 32-bit frequency pa-
rameter is controlled by a 4-bit FM Gain word in the programming
registers.
The MSB of the data word amplitude aligns with the MSB of the
DDS's 14-bit amplitude parameter. The 6 LSBs of the DDS's ampli-
tude parameter are assigned from bits <5:0> of the ASF register.
The resulting 14-bit word scales the amplitude from 0 to 1-2
The MSB of the data word phase aligns with the MSB of the DDS's
16-bit phase parameter. The 8 LSBs of the DDS's phase parameter
are assigned from bits <7:0> of the POW register. The resulting 16-
bit word offsets the phase from 0 to 2π(1-2
the maximum frequency range spanned by the data word.
Remarks
-14
.
-16
) radians.
-16
) radians.
PR06464-0-10/06(PrD)
AD9910
-14
.