Datasheet

ADS1255
ADS1256
SBAS288K − JUNE 2003 − REVISED SEPTEMBER 2013
www.ti.com
32
DRATE: A/D Data Rate (Address 03h)
Reset Value = F0h
BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0
DR7 DR6 DR5 DR4 DR3 DR2 DR1 DR0
The 16 valid Data Rate settings are shown below. Make sure to select a valid setting as the invalid settings may produce
unpredictable results.
Bits 7-0 DR[7: 0]: Data Rate Setting
(1)
11110000 = 30,000SPS (default)
11100000 = 15,000SPS
11010000 = 7,500SPS
11000000 = 3,750SPS
10110000 = 2,000SPS
10100001 = 1,000SPS
10010010 = 500SPS
10000010 = 100SPS
01110010 = 60SPS
01100011 = 50SPS
01010011 = 30SPS
01000011 = 25SPS
00110011 = 15SPS
00100011 = 10SPS
00010011 = 5SPS
00000011 = 2.5SPS
(1)
for f
CLKIN
= 7.68MHz. Data rates scale linearly with f
CLKIN
.
I/O: GPIO Control Register (Address 04
H
)
Reset Value = E0h
BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0
DIR3 DIR2 DIR1 DIR0 DIO3 DIO2 DIO1 DIO0
The states of these bits control the operation of the general-purpose digital I/O pins. The ADS1256 has 4 I/O pins: D3, D2,
D1, and D0/CLKOUT. The ADS1255 has two digital I/O pins: D1 and D0/CLKOUT. When using an ADS1255, the register
bits DIR3, DIR2, DIO3, and DIO2 can be read from and written to but have no effect.
Bit 7 DIR3, Digital I/O Direction for Digital I/O Pin D3 (used on ADS1256 only)
0 = D3 is an output
1 = D3 is an input (default)
Bit 6 DIR2, Digital I/O Direction for Digital I/O Pin D2 (used on ADS1256 only)
0 = D2 is an output
1 = D2 is an input (default)
Bit 5 DIR1, Digital I/O Direction for Digital I/O Pin D1
0 = D1 is an output
1 = D1 is an input (default)
Bit 4 DIR0, Digital I/O Direction for Digital I/O Pin D0/CLKOUT
0 = D0/CLKOUT is an output (default)
1 = D0/CLKOUT is an input
Bits 3-0 DI0[3:0]: Status of Digital I/O Pins D3, D2, D1, D0/CLKOUT
Reading these bits will show the state of the corresponding digital I/O pin, whether if the pin is configured as an
input or output by DIR3-DIR0. When the digital I/O pin is configured as an output by the DIR bit, writing to the
corresponding DIO bit will set the output state. When the digital I/O pin is configured as an input by the DIR bit,
writing to the corresponding DIO bit will have no effect. When DO/CLKOUT is configured as an output and
CLKOUT is enabled (using CLK1, CLK0 bits in the ADCON register), writing to DIO0 will have no effect.