Datasheet
www.ti.com
TSC2301 TOUCH SCREEN CONTROL REGISTERS
TSC2301 ADC Control Register (Page 1, Address 00H)
TSC2301
SLAS371D – SEPTEMBER 2002 – REVISED AUGUST 2004
This section describes each of the registers shown in the memory map of Figure 54 . The registers are grouped
according to the function they control. In the TSC2301, bits in control registers can refer to slightly different
functions depending upon whether you are reading the register or writing to it. A summary of all registers and bit
locations is shown in Table 4 .
The ADC in the TSC2301 is shared between all the different functions. A control register determines which input
is selected, as well as other options. The result of the conversion is placed in one of the result registers in Page
0 of memory, depending upon the function selected.
The ADC control register controls several aspects of the ADC. The register is formatted as follows:
Bit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
MSB LSB
PSM STS AD3 AD2 AD1 AD0 RS1 RS0 AV1 AV0 CL1 CL0 PV2 PV1 PV0 X
Bit 15 — PSM
Pen Status/Control Mode. Reading this bit allows the host to determine if the screen is touched. Writing to this bit
determines the mode used to read coordinates: host controlled or under control of the TSC2301 responding to a
screen touch. When reading, the PENSTS bit indicates if the pen is down or not. When writing to this register,
this bit determines if the TSC2301 controls the reading of coordinates, or if the coordinate conversions are
host-controlled. The default state is host-controlled conversions (0).
Table 5. PSM Bit Operation
PSM
Read/Write Value Description
Read 0 No screen touch detected (default)
Read 1 Screen touch detected
Write 0 Conversions controlled by host
Write 1 Conversions controlled by TSC2301
Bit 14 — STS
ADC Status. Reading this bit indicates if the converter is busy. Writing a 0 to this bit causes the touch screen
scans to continue until either the pen is lifted or the process is stopped. Continuous scans or conversions can be
stopped by writing a 1 to this bit. This immediately halts a conversion (even if the pen is still down) and causes
the ADC to power down. The default state is continuous conversions, but if this bit is read after a reset or
power-up, it reads 1.
Table 6. STS Bit Operation
STS
Read/Write Value Description
Read 0 Converter is busy
Read 1 Converter is not busy (default)
Write 0 Normal operation
Write 1 Stop conversion and power down
29