Datasheet

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COMMUNICATION PROTOCOL

Configuration Register 0

TSC2004

SBAS408E – JUNE 2007 – REVISED MARCH 2008

The TSC2004 is controlled entirely by registers. Reading and writing to these registers are accomplished by the

use of Control Byte 0, which includes a 4-bit address plus one read/write TSC register control bit. The data

registers defined in Table 10 are all 16-bit, right-adjusted. NOTE: Except for some configuration registers and the

Status register that are full 16-bit registers, the rest of the value registers are 12-bit (or 10-bit) data preceded by

four (or six) zeros.

Table 11. Configuration Register 0 (Reset Value = 4000h for Read; 0000h for Write)

MSB LSB

D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0

PSM STS RM CL1 CL0 PV2 PV1 PV0 PR2 PR1 PR0 SN2 SN1 SN0 DTW LSM

PSM— Pen status/control mode. Reading this bit allows the host to determine if the screen is touched. Writing to

this bit selects the mode used to control the flow of converter functions that are either initiated and/or controlled

by host or under control of the TSC2004 responding to a pen touch. When reading, the PSM bit indicates if the

pen is down or not. When writing to this register, this bit determines if the TSC2004 controls the converter

functions, or if the converter functions are host-controlled. The default state is the host-controlled converter

function mode (0). The other state (1) is the TSC-initiated scan function mode that must only collaborate with

C3-C0 = 0000 or 0001 in order to allow the TSC2004 to initiate and control the scan function for XYZ or XY when

a pen touch is detected.

Table 12. PSM Bit Operation

OPERATION VALUE DESCRIPTION

Read 0 No screen touch detected

Read 1 Screen touch detected

Write 0 Converter functions initiated and/or controlled by host

Write 1 Converter functions initiated and controlled by the TSC2004

STS— A/D converter status. When reading, this bit indicates if the converter is busy or not busy. Continuous

scans or conversions can be stopped by writing a '1' to this bit, immediately aborting the running converter

function (even if the pen is still down) and causing the A/D converter to power down. The default state for write is

0 (normal operation), and the default state for read is 1 (converter is not busy). NOTE: The same bit can be

written through Control Byte 1. This bit is self-clearing.

Table 13. STS Bit Operation

OPERATION VALUE DESCRIPTION

Read 0 Converter is busy

Read 1 Converter is not busy

Write 0 Normal operation

Write 1 Stop converter function and power down

RM— Resolution control. The A/D converter resolution is specified with this bit. See Table 14 for a description of

these bits. This bit is the same whether reading or writing, and defaults to 0. Note that the same bit can be

written through Control Byte 1.

Table 14. A/D Converter Resolution Control

RM FUNCTION

0 10-bit resolution. Power-up and reset default.

1 12-bit resolution

Product Folder Link(s): TSC2004