Datasheet
AD5272/AD5274 Data Sheet
Rev. D | Page 22 of 28
Table 13. Write and Read to RDAC and 50-TP memory
DIN SDO
1
Action
0x1C03 0xXXXX Enable update of wiper position and 50-TP memory contents through digital interface.
0x0500 0x1C03 Write 0x100 to the RDAC register, wiper moves to ¼ full-scale position.
0x0800 0x0500 Prepare data read from RDAC register.
0x0C00 0x100
Stores RDAC register content into 50-TP memory. 16-bit word appears out of SDO, where last 10-bits contain the
contents of the RDAC Register 0x100.
0x1800 0x0C00 Prepare data read of last programmed 50-TP memory monitor location.
0x0000 0xXX19
NOP Instruction 0 sends a 16-bit word out of SDO, where the six LSBs last 6-bits contain the binary address of the last
programmed 50-TP memory location, for example, 0x19 (see Table 16).
0x1419 0x0000 Prepares data read from Memory Location 0x19.
0x2000 0x0100
Prepare data read from the control register. Sends a 16-bit word out of SDO, where the last 10-bits contain the contents
of Memory Location 0x19.
0x0000 0xXXXX
NOP Instruction 0 sends a 16-bit word out of SDO, where the last four bits contain the contents of the control register.
If Bit C3 = 1, fuse program command successful.
1
X is don’t care.
Table 14. Control Register Bit Map
DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
0 0 0 0 0 0 C3 C2 C1 C0
Table 15. Control Register Description
Bit Name Description
C0 50-TP program enable
0 = 50-TP program disabled (default)
1 = enable device for 50-TP program
C1 RDAC register write protect
0 = wiper position frozen to value in 50-TP memory (default)
1
1 = allow update of wiper position through a digital interface
C2 Resistor performance enable
0 = RDAC resistor tolerance calibration enabled (default)
1 = RDAC resistor tolerance calibration disabled
C3 50-TP memory program success bit
0 = fuse program command unsuccessful (default)
1 = fuse program command successful
1
Wiper position is frozen to the last value programmed in the 50-TP memory. Wiper freezes to midscale if 50-TP memory has not been previously programmed.
Table 16. Memory Map
Command Number
Data Byte [DB9:DB8]
1
Register Contents
D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
5 X X X 0 0 0 0 0 0 0 Reserved
X X X 0 0 0 0 0 0 1 1st programmed wiper location (0x01)
X X X 0 0 0 0 0 1 0 2nd programmed wiper location (0x02)
X X X 0 0 0 0 0 1 1 3rd programmed wiper location (0x03)
X X X 0 0 0 0 1 0 0 4th programmed wiper location (0x04)
… … … … … … … … … … …
X X X 0 0 0 1 0 1 0 10th programmed wiper location (0xA)
X X X 0 0 1 0 1 0 0 20th programmed wiper location (0x14)
X X X 0 0 1 1 1 1 0 30th programmed wiper location (0x1E)
X X X 0 1 0 1 0 0 0 40th programmed wiper location (0x28)
X X X 0 1 1 0 0 1 0 50th programmed wiper location (0x32)
1
X is don’t care.