REV. B–14–
AD9845B
SERIAL INTERFACE TIMING AND INTERNAL REGISTER DESCRIPTION
Table I. Internal Register Map
Register Address Data Bits
Name A0 A1 A2 D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 D10
Operation 0 0 0 Channel Select Power-Down Software OB Clamp 0
1
1
2
0
1
0
1
0
1
CCD/AUX1/2 Modes Reset On/Off
VGA Gain 1 0 0 LSB MSB X
Clamp Level 0 1 0 LSB MSB X X X
Control 1 1 0 Color Steering Mode PxGA Clock Polarity Select for 0
1
0
1
Three- X
Selection On/Off SHP/SHD/CLP/DATA State
PxGA Gain0 0 0 1 LSB MSB X X X X X
PxGA Gain1 1 0 1 LSB MSB X X X X X
PxGA Gain2 0 1 1 LSB MSB X X X X X
PxGA Gain3 1 1 1 LSB MSB X X X X X
NOTES
1
Internal use only. Must be set to 0.
2
Must be set to 1.
SDATA
SCK
SL
RNW TEST BIT
0
A2 0A0 A1 D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 D10
t
DS
t
DH
t
LS
t
LH
NOTES
1. SDATA BITS ARE INTERNALLY LATCHED ON THE RISING EDGES OF SCK.
2. RNW = READ-NOT-WRITE. SET LOW FOR WRITE OPERATION.
3. TEST BITS = INTERNAL USE ONLY. MUST BE SET LOW.
4. SYSTEM UPDATE OF LOADED REGISTERS OCCURS ON SL RISING EDGE.
Figure 21. Serial Write Operation
SDATA
SCK
SL
RNW TEST BIT
10
0
A0 A1 D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 D10
t
DS
t
DH
t
LS
t
LH
NOTES
1. RNW = READ-NOT-WRITE. SET HIGH FOR READ OPERATION.
2. TEST BITS = INTERNAL USE ONLY. MUST BE SET LOW.
3. SERIAL DATA FROM THE SELECTED REGISTER IS VALID STARTING AFTER THE FIFTH SCK FALLING EDGE AND IS UPDATED ON
SCK FALLING EDGES.
t
DV
Figure 22. Serial Readback Operation
