Owner's manual

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Table Of Contents

Contents
- Figures
- Tables
- Revision History
Preface
- P.1 About the EP93xx User’s Guide
- P.2 Related Documents from Cirrus Logic
- P.3 Reference Documents
- P.4 Notational Conventions
- P.5 Register Example
Introduction
- 1.1 Introduction
- 1.2 EP93xx Features
- 1.3 EP93xx Processor Applications
- 1.4 EP93xx Processor Highlights
ARM920T Core and Advanced High-Speed Bus (AHB)
- 2.1 Introduction
- 2.2 Overview: ARM920T Core
- 2.3 AHB Decoder
MaverickCrunch Co-Processor
- 3.1 Introduction
- 3.2 Programming Examples
  - 3.2.1 Example 1
  - 3.2.2 Example 2
    - 3.2.2.1 C Code
    - 3.2.2.2 MaverickCrunch Assembly Language Instructions
- 3.3 DSPSC Register
- 3.4 ARM Co-Processor Instruction Format
- 3.5 Instruction Set for the MaverickCrunch Co-Processor
Boot ROM
- 4.1 Introduction
  - 4.1.1 Boot ROM Hardware Operational Overview
    - 4.1.1.1 Memory Map
  - 4.1.2 Boot ROM Software Operational Overview
- 4.2 Boot Options
System Controller
- 5.1 Introduction
- 5.2 Registers
Vectored Interrupt Controller
- 6.1 Introduction
- 6.2 Registers
Raster Engine With Analog/LCD Integrated Timing and Interface
- 7.1 Introduction
- 7.2 Features
- 7.3 Raster Engine Features Overview
- 7.4 Functional Details
- 7.5 Registers
Graphics Accelerator
- 8.1 Overview
- 8.2 Block Processing Modes
- 8.3 Line Draws
  - 8.3.1 Breshenham Line Draws
  - 8.3.2 Pixel Step Line Draws
- 8.4 Memory Organization for Graphics Accelerator
- 8.5 Register Programming
  - 8.5.1 Word Count
    - 8.5.1.1 Example: 8 BPP mode
    - 8.5.1.2 Example: 24 BPP (packed) mode
  - 8.5.2 Pixel End and Start
- 8.6 Register Usage
- 8.7 Registers
1/10/100 Mbps Ethernet LAN Controller
- 9.1 Introduction
- 9.2 Descriptor Processor
- 9.3 Registers
DMA Controller
- 10.1 Introduction
- 10.2 Registers
  - 10.2.1 DMA Controller Memory Map
  - 10.2.2 Internal M2P/P2M Channel Register Map
Universal Serial Bus Host Controller
- 11.1 Introduction
  - 11.1.1 Features
- 11.2 Overview
- 11.3 Registers
Static Memory Controller
- 12.1 Introduction
- 12.2 Static Memory Controller Operation
- 12.3 PCMCIA Interface (EP9315 Processor Only)
- 12.4 PC Card Memory-Mode Enable Signals
- 12.5 PC Card Memory Mapping
- 12.6 Registers
  - 12.6.1 Bank Configuration Registers
  - 12.6.2 PCMCIA Configuration Registers (EP9315 Processor Only)
SDRAM, SyncROM, and SyncFLASH Controller
- 13.1 Introduction
- 13.2 Booting from SyncROM or SyncFLASH
- 13.3 Address Pin Usage
- 13.4 SDRAM Initialization
- 13.5 Programming Mode Register: SDRAM Or SyncROM Device
- 13.6 SDRAM Self Refresh
  - 13.6.1 Entering Self Refresh Mode
  - 13.6.2 Exiting Self Refresh Mode
- 13.7 Programming Registers: SyncFLASH Device
- 13.8 External Synchronous Memory System
  - 13.8.1 Chip Select SDCSN[3:0] Decoding
  - 13.8.2 Address/Data/Control Required by Memory System
- 13.9 Registers
UART1 With HDLC and Modem Control Signals
- 14.1 Introduction
- 14.2 UART Overview
- 14.3 Modem
- 14.4 HDLC
- 14.5 UART1 Package Dependency
  - 14.5.1 Clocking Requirements
  - 14.5.2 Bus Bandwidth Requirements
- 14.1 Registers
UART2
- 15.1 Introduction
- 15.2 IrDA SIR Block
- 15.3 UART2 Package Dependency
  - 15.3.1 Clocking Requirements
  - 15.3.2 Bus Bandwidth Requirements
- 15.4 Registers
UART3 With HDLC Encoder
- 16.1 Introduction
- 16.2 Implementation Details
- 16.3 Registers
IrDA
- 17.1 Introduction
- 17.2 IrDA Interfaces
- 17.3 Shared IrDA Interface Feature
- 17.4 Medium IrDA Specific Features
  - 17.4.1 Introduction
    - 17.4.1.1 Bit Encoding
    - 17.4.1.2 Frame Format
  - 17.4.2 Functional Description
- 17.5 Fast IrDA Specific Features
- 17.6 Registers
Timers
- 18.1 Introduction
- 18.2 Registers
Watchdog Timer
- 19.1 Introduction
- 19.1 Registers
Real Time Clock With Software Trim
- 20.1 Introduction
  - 20.1.1 Software Trim
  - 20.1.2 Reset Control
- 20.1 Registers
I2S Controller
- 21.1 Introduction
- 21.2 I2S Transmitter Channel Overview
- 21.3 I2S Receiver Channel Overview
  - 21.3.1 Receiver FIFO’s
- 21.4 I2S Master Clock Generation
- 21.5 I2S Bit Clock Rate Generation
  - 21.5.1 Example of the Bit Clock Generation.
  - 21.5.2 Example of Right Justified LRCK format
- 21.6 Interrupts
- 21.7 Registers
AC’97 Controller
- 22.1 Introduction
- 22.2 Interrupts
  - 22.2.1 Channel Interrupts
  - 22.2.2 Global Interrupts
- 22.3 System Loopback Testing
- 22.4 Registers
Synchronous Serial Port
- 23.1 Introduction
- 23.2 Features
- 23.3 SSP Functionality
- 23.4 SSP Pin Multiplex
- 23.5 Configuring the SSP
- 23.6 Registers
Pulse Width Modulator
- 24.1 Introduction
- 24.2 Theory of Operation
  - 24.2.1 PWM Programming Examples
  - 24.2.2 Programming Rules
- 24.3 Registers
Analog Touch Screen Interface
- 25.1 Introduction
- 25.2 Touch Screen Controller Operation
- 25.3 Registers
Keypad Interface
- 26.1 Introduction
- 26.2 Theory of Operation
- 26.3 Registers
IDE Interface
- 27.1 Introduction
- 27.2 Theory of Operation
- 27.3 Registers
GPIO Interface
- 28.1 Introduction
- 28.2 Registers
Security
- 29.1 Introduction
- 29.2 Features
- 29.3 Contact Information
- 29.4 Registers
Glossary
EP93XX Register List

25-4 DS785UM1

Analog Touch Screen Interface

EP93xx User’s Guide

25.2.1 Touch Screen Scanning: Four-wire and Eight-wire Operation

Figure 25-2 shows control for an 8-wire analog resistive touch screen. The register values

TSDetect, TSDischarge, TSXSample, and TSYSample are derived from the switch positions

in the diagram. These values are listed in Table 25-2.

The left most part of the diagram shows how the switches are driven to detect a touch press.

This configuration is controlled by the TSDetect register.

The second part of the diagram shows all lines of the touch screen switched to ground for

discharging as controlled by the TSDischarge register.

The third example shows a voltage driven across the X-axis with the A / D sample input

connected to both Y-axis lines and the A / D referenced to the SX feedback lines as

controlled by the TSXSample register.

The right most part of the diagram shows a voltage driven across the Y-axis with the A / D

sample input connected to both X-axis lines and the A / D referenced to the SY feedback

lines for digitization as controlled by the TSYSample register.

Each time the analog switching configuration is changed, an appropriate time interval must

be provided for the circuit to stabilize due to the touch screen capacitance, and any EMI

filtering provided on the signals. This is controlled by the DLY field in the TSSetup register.

The analog touch screen interface circuitry is internally connected to a signed 12-bit analog-

to-digital converter. The 12-bit digital result is held stable until another sample is requested.

The controller reads the digital value by issuing a read pulse. This read pulse signal from the

controller is also used as a convert command for the analog-to-digital converter to begin

conversion of its next sample. The output of the ADC is a signed value. For the comparison

functions of the touch controller to work correctly, the TSSetup2.SIGND bit should be set.

The flow chart in Figure 25-4 demonstrates the sample process used for determining touch

input on a touch screen. The ARM Core must load all of the setup registers for the touch

Bit 18 sY- AGND -

Bit 19 X+ AVDD SW19 = HIGH and SW11 = LOW and SW0 = LOW

Bit 20 Y+ AVDD SW20 = HIGH and SW13 = LOW and SW2 = LOW

Bit 21 Y- AVDD SW21 = HIGH and SW14 = LOW and SW3 = LOW

Bit 22 X+ Pull-up to AVDD

SW22 = HIGH and SW11 = LOW and

(SW0 = LOW or the bus SW[7-0] = 0x01)

Bit 23 Y+ Pull-up to AVDD

SW23 = HIGH and SW13 = LOW and

(SW2 = LOW or the bus SW[7-0] = 0x04)

Bit 24 sX+ ADC REF+ -

Bit 25 sX- ADC REF- -

Bit 26 sY+ ADC REF+ -

Bit 27 sY- ADC REF- -

Bit 28

TOUCH_PRES

S gate

Touch_Press

NAND gate

Gates input to prevent oscillations

Bit 29 DAC ADC input DAC to ADC feedback test switch

Bit 30 VBAT ADC input Load Resistor Also gates PRSTn for measuring battery with load

Table 25-1. Switch Definitions and Logical Safeguards to Prevent Physical Damage (Continued)