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Device in any operation mode
Program GPIO register?
End of GPIO register programming
Yes
No
CS
CS
GPIO register
programming
SDI: DI15..12 = 0100
Refer table 9 for DI11..00 data
42
ADS7950, ADS7951, ADS7952, ADS7953, ADS7954, ADS7955
ADS7956, ADS7957, ADS7958, ADS7959, ADS7960, ADS7961
SLAS605C – JUNE 2008 – REVISED JULY 2018
Product Folder Links:
ADS7950 ADS7951 ADS7952 ADS7953 ADS7954 ADS7955 ADS7956 ADS7957 ADS7958
Copyright © 2008–2018, Texas Instruments Incorporated
Table 10. Ideal Input Voltages for 8-Bit Devices and Digital Output Codes for 8-Bit Devices
(ADS7958/59/60/61)
DESCRIPTION
ANALOG VALUE
DIGITAL OUTPUT
Full scale range
Range 1
→
V
REF
Range 2
→
2×V
REF
STRAIGHT BINARY
Least significant bit (LSB)
V
REF
/ 256
2V
REF
/ 256
BINARY CODE
HEX CODE
Full scale
V
REF
– 1 LSB
2V
REF
– 1 LSB
1111 1111
FF
Midscale
V
REF
/ 2
V
REF
1000 0000
80
Midscale – 1 LSB
V
REF
/ 2 – 1 LSB
V
REF
– 1 LSB
0111 1111
7F
Zero
0 V
0 V
0000 0000
00
8.5.2 GPIO Registers
NOTE
GPIO 0, 1, 2, and 3 are available in the TSSOP packages. Only GPIO 0 is available in the
VQFN packages.
The device has four general purpose input and output (GPIO) pins. Each of the four pins can be independently
programmed as general purpose output (GPO) or general purpose input (GPI). It is also possible to use the
GPIOs for some pre-assigned functions (refer to
for details). GPO data can be written into the device
through the SDI line. The device refreshes the GPO data on every CS falling edge as per the SDI data written in
the previous frame. Similarly, the device latches GPI status on the CS falling edge and outputs it on SDO (if GPI
is read enabled by writing DI04 = 1 during the previous frame) in the same frame starting on the CS falling edge.
The details regarding programming the GPIO registers are illustrated in the flowchart in
.
lists
the details regarding GPIO Register programming settings.
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 58. GPIO Program Register Programming Flowchart