Deleted Setting Up The Digital Interface Section And Figure 5; Renumbered Sequentially; Added Operating The Software Section; Changes To Figure 5 To Figure 8 And Programming Method: Hardware Or Software Section; Operating The Software - Analog Devices EVAL-CN-304-SDZ User Manual

EVAL-CN-304-SDZ Evaluation Board User Guide

OPERATING THE SOFTWARE

Select External MCLK Frequency
Having selected the digital interface specifics, next use the
MCLK box to choose which frequency to use. The boards are
supplied with a 75 MHz general oscillator. If a different clock
source is required, the CLK1 SMB connector can be used to
supply a different MCLK value.
Two options for the general oscillator include the AEL3013
oscillators from AEL Crystals and the SG-310SCN oscillators
from Epson Electronics.
Figure 5. MCLK Input
Programming Method: Hardware or Software
Functions that select frequency and phase registers, reset internal
registers, and power down the DAC can be implemented by
using either software or hardware. Click Software or Hardware
to select the programming method (see Figure 6). By choosing
hardware, the appropriate hardware control pins are used to
control these functions. By choosing software, the appropriate
software control bits are used to control these functions.
Figure 6. Programming Method
Loading Frequency and Phase Registers
The desired output frequency and output phase can be loaded
using the inputs shown in Figure 7. Either the FREQ 0 register or
the FREQ 1 register can be loaded with frequency data. The
frequency data is loaded in megahertz, and the equivalent
hexadecimal code is shown to the right once data is entered; press
Enter to load the data. When data is loaded, the output appears on
the IOUT and IOUTB pins. Similarly, select either the PHASE 0
register or the PHASE 1 register and the phase data loads in
degrees.
The analog output frequency from the
28
f /2 × FREQREG
MCLK
where FREQREG is the value loaded into the selected frequency
register in decimals. This signal is phase shifted by
2π/4096 × PHASEREG
where PHASEREG is the value contained in the selected phase
register in decimals.
FSK and PSK Functionality
In software mode, the
functionality by entering the bit rate in milliseconds and by
clicking the PSK or FSK button (see Figure 8).
Rev. B | Page 5 of 12
AD9834
Figure 7. Frequency and Phase Load
AD9834 can be set up for FSK or PSK
Figure 8. FSK and PSK Functionality
UG-266
is defined by