Datasheet
TSC2101
SLAS392D− JUNE 2003 − REVISED MAY 2005
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43
Where:
VREF is the SAR ADC reference
Vsar is input to the SAR ADC
The TSC2101 supports programmable auto−auxiliary measurement mode, which can be enabled using control
register 0CH/page 1. In this mode, the TSC2101 can auto start the auxiliary measurement after a
programmable interval. The user can program minimum and maximum threshold values through a register. If
the measurement goes outside the threshold range, the TSC2101 sets a flag in the read only control register
0CH/page 1, which gets cleared after the flag is read. The TSC2101 can also be configured to send an active
high interrupt over GPIO1 by setting D9 of control register 0CH/page 1. The duration of the interrupt is
approximately 2 ms.
Auxiliary measurement can only be done in host−controlled mode.
See the section Conversion Time Calculation for the TSC2101 and subsection Non Touch Measurement
Operation in this data sheet for timing diagram and conversion time calculation
Port Scan
If making measurements of VBAT, AUX1, and AUX2 is desired on a periodic basis, the Port Scan mode can
be used. This mode causes the TSC2101 to sample and convert battery input and both auxiliary inputs. At the
end of this cycle, the battery and auxiliary result registers contain the updated values. Thus, with one write to
the TSC2101, the host can cause three different measurements to be made.
Port Scan can only be done in host-controlled mode. See the section Issues at the end of this data sheet for
details of a known issue with this mode.
See the section Conversion Time Calculation for the TSC2101 and subsection Port Scan Operation in this data
sheet for timing diagrams and conversion time calculations.
Buffer Mode
The TSC2101 supports a programmable buffer mode, which is applicable for both touch screen related
conversion (X, Y, Z1, Z2) and nontouch screen related conversion (BAT, AUX1, AUX2, TEMP1, TEMP2). Buffer
mode is implemented using a circular FIFO with a depth of 64. The number of interrupts required to be serviced
by a host processor can be reduced significantly buffer mode. Buffer mode can be enabled using control register
02H/page1.
Figure 35. Circular Buffer