Register Map; Control Register (Register Address 0X80, Register Address 0X81) - Analog Devices AD5934 Manual

AD5934

REGISTER MAP

Table 7.
Register Name
Control
Start Frequency
Frequency Increment
Number of Increments
Number of Settling Time Cycles
Status
Real Data
Imaginary Data
CONTROL REGISTER (REGISTER ADDRESS 0x80,
REGISTER ADDRESS 0x81)
The AD5934 contains a 16-bit control register (Register Address
0x80 and Register Address 0x81) that sets the control modes.
The default value of the control register upon reset is as follows:
D15 to D0 is reset to 0xA000 upon power-up.
The four MSBs of the control register are decoded to provide
control functions, such as performing a frequency sweep,
powering down the part, and controlling various other functions
defined in the control register map.
The user can choose to write only to Register Address 0x80 and
to not alter the contents of Register Address 0x81. Note that the
control register should not be written to as part of a block write
command. The control register also allows the user to program
the excitation voltage and set the system clock. A reset command
to the control register does not reset any programmed values
associated with the sweep (that is, start frequency, number of
increments, frequency increment). After a reset command,
an initialize with start frequency command must be issued to
the control register to restart the frequency sweep sequence
(see Figure 30).
Table 8. D10 to D9 Control Register Map
D10 D9 Range No.
0 0 1
0 1 3
1 0 4
1 1 2
Register Address
0x80
0x81
0x82
0x83
0x84
0x85
0x86
0x87
0x88
0x89
0x8A
0x8B
0x8F
0x94
0x95
0x96
0x97
Output Voltage Range
2.0 V p-p typical
200 mV p-p typical
400 mV p-p typical
1.0 V p-p typical
Rev. A | Page 22 of 40
Bits
D15 to D8
D7 to D0
D23 to D16
D15 to D8
D7 to D0
D23 to D16
D15 to D8
D7 to D0
D15 to D8
D7 to D0
D15 to D8
D7 to D0
D7 to D0
D15 to D8
D7 to D0
D15 to D8
D7 to D0
Table 9. D11 and D8 to D0 Control Register Map
Bits Description
D11 No operation
D8 PGA gain; 0 = ×5, 1 = ×1
D7 Reserved; set to 0
D6 Reserved; set to 0
D5 Reserved; set to 0
D4 Reset
D3 External system clock; set to 1
Internal system clock; set to 0
D2 Reserved; set to 0
D1 Reserved; set to 0
D0 Reserved; set to 0
Table 10. D15 to D12 Control Register Map
D15 D14 D13 D12
0 0 0 0
0 0 0 1
0 0 1 0
0 0 1 1
0 1 0 0
1 0 0 0
1 0 0 1
1 0 1 0
1 0 1 1
1 1 0 0
1 1 0 1
Function
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read only
Read only
Read only
Read only
Read only
Description
No operation
Initialize with start frequency
Start frequency sweep
Increment frequency
Repeat frequency
No operation
No operation
Power-down mode
Standby mode
No operation
No operation