Texas Instruments MSP430x4xx Computer Hardware User Manual


 
Scan IF Operation
24-12 Scan IF
For each input there are two DAC registers to set the reference level as listed
in Table 243. Together with the last stored output of the comparator,
SIFxOUT, the two levels can be used as an analog hysteresis as shown in
Figure 246. The individual settings for the four inputs can be used to
compensate for mismatches between the sensors.
Table 243.Selected DAC Registers
Selected Output Bit,
SIFxOUT
Last Value of
SIFxOUT
DAC Register Used
SIF0OUT 0 SIFDACR0
1 SIFDACR1
SIF1OUT 0 SIFDACR2
1 SIFDACR3
SIF2OUT 0 SIFDACR4
1 SIFDACR5
SIF3OUT 0 SIFDACR6
1 SIFDACR7
Figure 246. Analog Hysteresis With DAC Registers
DAC Output Voltage
Input Voltage
SIF1OUT
Time
SIFDACR2
SIFDACR3
When TESTDX = 1, the SIFDACR6 and SIFDACR7 registers are used as the
comparator reference as described in Table 244.
Table 244.DAC Register Select When TESTDX = 1
SIFTESTS1(tsm) DAC Register Used
0 SIFDACR6
1 SIFDACR7