AT42QT1085_14 Datasheet, PDF (1/40 Pages) ATMEL Corporation – Object Protocol Guide

Atmel AT42QT1085
Object Protocol Guide
1. Introduction
This document describes in detail the Object Protocol for the AT42QT1085
(QT1085).
The Object Protocol provides a single common interface across the Atmel^®
QTouch^® touch sensor controllers. This allows the different features in each
controller to be configured in a consistent manner. It makes the future expansion of
features and simple product upgrades possible, whilst allowing backwards
compatibility for the host driver and application code.
2. Overview
2.1 Memory Map Structure
The protocol is designed to control the processing chain in a modular manner. This
is achieved by breaking the features of the device into objects that can be
controlled individually. Each object represents a certain feature or function of the
device, such as a touchscreen or a key array. Objects can be disabled or enabled
as needed.
Each object has its own configuration memory. The objects are stacked together to
produce an object-based memory map. A generalized structure of this memory
map is shown in Figure 2-1.
There are some special objects that can use their memory space for a unique
purpose. One example is the Command Processor T6 object, which executes a
command when a certain value is written into its memory space. Another example
is the Message Processor T5 object, which outputs messages by having the host
read its memory space.
From Figure 2-1 on page 2 it can be seen that the memory map contains two main
sections:
 An Information Block. This documents which objects are contained in the
memory map for the device (see Section 2.2 on page 2). It is further sub-
divided into the ID Information Block and the Object Table (see Section 2.4
on page 4).
 The objects themselves (see Section 2.5 on page 5).
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