
AD9929
INITIAL START-UP SEQUENCE
Recommended Start-Up Sequence for Master Mode
When the AD9929 is powered up, the following sequence is
recommended (refer to Figure 66 for each step).
Rev. A | Page 55 of 64
1.
Turn on power supplies as described in the Power Supply
Sequencing section.
Apply the CLI master clock input.
CLI is output on DCLK2 Pin 16 at this time.
Reset the internal AD9929 registers. Write a 0x000000 to
the SW_RESET register (Address 0x00). This sets all
internal register values to their default values. (This step is
optional because there is an internal power-on reset circuit
that is applied at power-up.)
Program DIGSTBY and AFESTBY registers (Address 0x05)
= 1 and all other necessary control registers.
2.
3.
4.
5.
6.
7.
8.
Program system registers (Address 0x20).
Program Mode_A registers (Address 0x21).
Program Mode_B registers (Address 0x22).
Program OUTCONT_REG register (Address 0x05) = 1.
(The internal OUTCONT signal is asserted high at this
time. This enables the digital outputs.)
Program control register MODE (Address 0x0A) = 0. This
selects Mode_A operation. (This step is optional because
the AD9929 defaults to Mode_A at power-up.)
10.
Program control register MODE (Address 0x0A) = 1. This
selects Mode_B operation. Note: Complete this write at
least 4 CLI cycles before the start of the next field.
9.
AD9929
POWER-UP
SEQUENCE
SERIAL
VD
(OUTPUT)
1 H
ODD FIELD
EVEN FIELD
(ODIGITAL
H2, RG, MSHUT, STROBE
H1, VSUB, FD
(OUTPHD
1 V
1
(INTERNOUTCONT
DCLK1
3
5
7
NOTES
1
OUTCONT IS AN INTERNAL SIGNAL THAT IS CONTROLLED USING REGISTER OUTCONT_REG (ADDRESS 0x05).
2
DCLK2 WILL BE OUTPUT ON THE FD/DCLK2 PIN 16 PROVIDING REGISTER DCLK2SEL (ADDRESS 0xD5) = 1.
THE DCLK2SEL REGISTER DEFAULTS TO 1 AT POWER-UP.
3
IT TAKES 11 CLI CLOCKS FROM WHEN OCONT GOES HIGH UNTIL VD, HD, AND DIGITAL OUTPUT DATA IS VALID.
4
THERE IS A 500
μ
S SETTLING TIME FROM WHEN THE DIGSTBY REGISTER IS SET TO WHEN THE DCLK1 IS STABLE.
ODD FIELD
t
SETTLING4
(INPCLI
2
(DCLK2
0
t
DELAY3
t
PWR
Figure 66. Recommended Start-Up Sequence and Synchronization, Master Mode