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Touch Sensor Short-Circuit Test

TSC2005

SBAS379C – DECEMBER 2006 – REVISED MARCH 2008

If the TBM bits of CFR1 detailed in Table 20 are all set to '1', a short-circuit in the touch sensor can be detected.

C3-C0 = 1011: PINTDAV = 0 during this short-circuit test. A '1' shown at end of the test indicates there is no

short-circuit detected (through X-axis) between the flex and stable layers. If there is a short-circuit detected,

PINTDAV stays low until a stop bit (STS set to '1') is issued.

C3-C0 = 1100: Reserved.

RM—Resolution select. If RM = 1, the conversion result resolution is 12-bit; otherwise, the resolution is 10-bit.

This bit is the same RM bit shown in CFR0.

SWRST—Software reset input. All register values are set to default value if a '1' is written to this bit. This bit must

be set to '0' in Control Byte 1 in order to cancel the software reset and resume normal operation.

STS—Stop bit for all converter functions. When writing a '1' to this register, this bit aborts the converter function

currently running in the TSC2005. A '0' must be written to this register in order to end the stop bit. This bit can

only stop converter functions; it does not reset any data, status, or configuration registers. This bit is the same

STS bit shown in CFR0, but can only be read through the CFR0 register with different interpretations.

Table 8. STS Bit Operation

OPERATION

VALUE

DESCRIPTION

Write

0

Normal operation

Write

1

Stop converter functions and power down

Table 9. Control Byte 0 Bit Register Description (D7 = 0)

BIT

NAME

DESCRIPTION

1: Control Byte 1—start conversion, channel select, and converison-related configuration

D7

Control Byte ID

0: Control Byte 0—read/write data registers and non-conversion-related controls

D6-D3

A3-A0

Register Address Bits as detailed in Table 10

D2

RESERVED

A '0' must be set in this bit for normal operation

Power Not Down Control

1: A/D converter biasing circuitry is always on between conversions, but is shut down after the converter

D1

PND0

function stops

0: A/D converter biasing circuitry is shut down either between conversions or after the converter function

stops

TSC Internal Register Data Flow Control

D0

R/W

1: Read from TSC internal registers

0: Write to TSC internal registers

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