AD9850

–10–

REV. E

Table II. Factory-Reserved Internal Test Control Codes

Loading Format

Factory-Reserved Codes

Parallel

1) W0 = XXXXXX10

2) W0 = XXXXXX01

Serial

1) W32 = 1; W33 = 0

2) W32 = 0; W33 = 1

3) W32 = 1; W33 = 1

Table III. 8-Bit Parallel-Load Data/Control Word Functional Assignment

Word

data[7]

data[6]

data[5]

data[4]

data[3]

data[2]

data[1]

data[0]

W0

Phase-b4

Phase-b3

Phase-b2

Phase-b1

Phase-b0

Power-Down

Control

Control

(MSB)

(LSB)

W1

Freq-b31

Freq-b30

Freq-b29

Freq-b28

Freq-b27

Freq-b26

Freq-b25

Freq-b24

(MSB)

W2

Freq-b23

Freq-b22

Freq-b21

Freq-b20

Freq-b19

Freq-b18

Freq-b17

Freq-b16

W3

Freq-b15

Freq-b14

Freq-b13

Freq-b12

Freq-b11

Freq-b10

Freq-b9

Freq-b8

W4

Freq-b7

Freq-b6

Freq-b5

Freq-b4

Freq-b3

Freq-b2

Freq-b1

Freq-b0

(LSB)

W0*

W1

W2

W3

W4

VALID DATA

OLD FREQ (PHASE)

NEW FREQ (PHASE)

*OUTPUT UPDATE CAN OCCUR AFTER ANY WORD LOAD

AND IS ASYNCHRONOUS WITH THE REFERENCE CLOCK

DATA

W CLK

REF CLK

COS OUT

DATA SETUP TIME

3.5ns

DATA HOLD TIME

3.5ns

W CLK HIGH

3.5ns

W CLK LOW

3.5ns

CLK DELAY AFTER FQ_UD

3.5ns

FQ UD HIGH

7.0ns

FQ UD LOW

7.0ns

FQ UD DELAY AFTER W CLK

7.0ns

OUTPUT LATENCY FROM FQ UD

FREQUENCY CHANGE

18 CLOCK CYCLES

PHASE CHANGE

13 CLOCK CYCLES

SYMBOL

DEFINITION

MIN

FQ UD

Figure 18. Parallel-Load Frequency/Phase Update Timing Sequence