Datasheet

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SLAS284A – AUGUST 2000 – REVISED DECEMBER 2002
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Control Register 0 (see Table 7)
BIT 11 BIT 10 BIT 9 BIT 8 BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0
0 0 TEST1 TEST0 SCAN DIFF1 DIFF0 CHSEL1 CHSEL0 PD RESERVED VREF
Table 8. Control Register 0 Bit Functions
BITS
RESET
VALUE
NAME FUNCTION
0 0 VREF Vref select:
Bit 0 = 0 → The internal reference is used
Bit 0 = 1 → The external reference voltage is used for the ADC
1 0 RESERVED RESERVED
2 0 PD Power down.
Bit 2 = 0 → The ADC is active
Bit 2 = 1 → Power down
The reading and writing to and from the digital outputs is possible during power down.
3, 4 0,0 CHSEL0,
CHSEL1
Channel select
Bit 3 and bit 4 select the analog input channel of the ADC. Refer to Table 9.
5,6 1,0 DIFF0, DIFF1 Number of differential channels
Bit 5 and bit 6 contain information about the number of selected differential channels. Refer to Table 9.
7 0 SCAN Autoscan enable
Bit 7 enables or disables the autoscan function of the ADC. Refer to Table 9.
8,9 0,0 TEST0,
TEST1
Test input enable
Bit 8 and bit 9 control the test function of the ADC. Three different test voltages can be measured. This
feedback allows the check of all hardware connections and the ADC in its bits.
Refer to Table 10 for selection of the three different test voltages.