Datasheet

Deviceinanyoperationmode
Yes
No
CS
CS
Entryinto Auto 1
register
programming
sequence
CS
Auto 1 register
programming
Program Auto1register?
SDI:DI15..12=1000
(Deviceenters Auto1programmingsequence)
SDI:DI15..0aspertables4,5
Endof Auto1registerprogramming
ADS7950, ADS7951, ADS7952, ADS7953
ADS7954, ADS7955, ADS7956, ADS7957
ADS7958, ADS7959, ADS7960, ADS7961
SLAS605A –JUNE 2008–REVISED JANUARY 2010 www.ti.com
The Auto-1 Program Register is programmed (once on powerup or reset) to pre-select the channels for the
Auto-1 sequence. Auto-1 Program Register programming requires two CS frames for complete programming. In
the first CS frame the device enters the Auto-1 register programming sequence and in the second frame it
programs the Auto-1 Program Register. Refer to Table 2, Table 3, and Table 4 for complete details.
NOTE: The device continues its operation in selected mode during programming. SDO is valid, however it is not possible to
change the range or write GPIO data into the device during programming.
Figure 52. Auto-1 Register Programming Flowchart
Table 3. Program Register Settings for Auto-1 Mode
DESCRIPTION
RESET
BITS
STATE
LOGIC STATE FUNCTION
FRAME 1
DI15-12 NA 1000 Device enters Auto-1 program sequence. Device programming is done in the next frame.
DI11-00 NA Do not care
FRAME 2
DI15-00 All 1s 1 (individual bit) A particular channel is programmed to be selected in the channel scanning sequence. The
channel numbers are mapped one-to-one with respect to the SDI bits; e.g.
DI15 → Ch15, DI14 → Ch14 … DI00 → Ch00
A particular channel is programmed to be skipped in the channel scanning sequence. The
0 (individual bit) channel numbers are mapped one-to-one with respect to the SDI bits; e.g.
DI15 → Ch15, DI14 → Ch14 … DI00 → Ch00
Table 4. Mapping of Channels to SDI Bits for 16,12,8,4 Channel Devices
Device
(1)
SDI BITS
DI15 DI14 DI13 DI12 DI11 DI10 DI09 DI08 DI07 DI06 DI05 DI04 DI03 DI02 DI01 DI00
16 Chan 1/0 1/0 1/0 1/0 1/0 1/0 1/0 1/0 1/0 1/0 1/0 1/0 1/0 1/0 1/0 1/0
12 Chan X X X X 1/0 1/0 1/0 1/0 1/0 1/0 1/0 1/0 1/0 1/0 1/0 1/0
8 Chan X X X X X X X X 1/0 1/0 1/0 1/0 1/0 1/0 1/0 1/0
4 Chan X X X X X X X X X X X X 1/0 1/0 1/0 1/0
(1) When operating in Auto-1 mode, the device only scans the channels programmed to be selected.
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Product Folder Link(s): ADS7950, ADS7951, ADS7952, ADS7953 ADS7954, ADS7955, ADS7956, ADS7957 ADS7958,
ADS7959, ADS7960, ADS7961