Ad9843a – Analog Devices AD9843A User Manual
Page 10
AD9843A
–10–
REV. 0
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
**
0
*
0
*
0
*
CCD/AUX
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
0
*
0
*
0
* CDS Gain Clock Polarity Select for
0
*
0
*
Three-
X
On/Off
SHP/SHD/CLP/DATA
State
CDS Gain
0
0
1
LSB
MSB
X
X
X
X
X
*
Internal use only, must be set to zero.
**Should be set to one.
SDATA
SCK
SL
RNW
TEST
0
A2
0
A0
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 BIT = INTERNAL USE ONLY. MUST BE SET LOW.
4. SYSTEM UPDATE OF LOADED REGISTERS OCCURS ON SL RISING EDGE.
Figure 8. Serial Write Operation
SDATA
SCK
SL
RNW
TEST
1
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 5TH SCK FALLING EDGE, AND IS UPDATED ON SCK
FALLING EDGES.
t
DV
A2
Figure 9. Serial Readback Operation
SDATA
SCK
SL
A0
A1
D0
D2
D3
D10
RNW
0
0
D9
0
0
0
D0
1
2
17
35
34
27
26
16
6
5
4
3
44
...
...
...
...
10 BITS
AGC GAIN
D7
D0
D9
...
...
...
...
...
NOTES:
1. ANY NUMBER OF ADJACENT REGISTERS MAY BE LOADED SEQUENTIALLY, BEGINNING WITH THE LOWEST ADDRESS AND INCREMENTING
ONE ADDRESS AT A TIME.
2. WHEN SEQUENTIALLY LOADING MULTIPLE REGISTERS, THE EXACT REGISTER LENGTH (SHOWN ABOVE) MUST BE USED FOR EACH REGISTER.
3. ALL LOADED REGISTERS WILL BE SIMULTANEOUSLY UPDATED WITH THE RISING EDGE OF SL.
8 BITS
CLAMP LEVEL
10 BITS
CONTROL
11 BITS
OPERATION
D1
D0
D2
D3
D1
18
19
20
7
8
9
Figure 10. Continuous Serial Write Operation to Multiple Registers