Owner's manual
Table Of Contents
- Contents
- Preface
- Introduction
- 1.1 Introduction
- 1.2 EP93xx Features
- 1.3 EP93xx Processor Applications
- 1.4 EP93xx Processor Highlights
- 1.4.1 High-Performance ARM920T Core
- 1.4.2 MaverickCrunch™ Co-processor for Ultra-Fast Math Processing
- 1.4.3 MaverickKey™ Unique ID Secures Digital Content in OEM Designs
- 1.4.4 Integrated Multi-Port USB 2.0 Full Speed Hosts with Transceivers
- 1.4.5 Integrated Ethernet MAC Reduces BOM Costs
- 1.4.6 8x8 Keypad Interface Reduces BOM Costs
- 1.4.7 Multiple Booting Mechanisms Increase Flexibility
- 1.4.8 Abundant General Purpose I/Os Build Flexible Systems
- 1.4.9 General-Purpose Memory Interface (SDRAM, SRAM, ROM, FLASH)
- 1.4.10 12-Bit Analog-to-Digital Converter (ADC) Provides an Integrated Touch-Screen Interface or General ADC Functionality
- 1.4.11 Raster Analog / LCD Controller
- 1.4.12 Graphics Accelerator
- 1.4.13 PCMCIA Interface
- ARM920T Core and Advanced High-Speed Bus (AHB)
- MaverickCrunch Co-Processor
- 3.1 Introduction
- 3.2 Programming Examples
- 3.3 DSPSC Register
- 3.4 ARM Co-Processor Instruction Format
- 3.5 Instruction Set for the MaverickCrunch Co-Processor
- 3.5.1 Load and Store Instructions
- 3.5.2 Move Instructions
- 3.5.3 Accumulator and DSPSC Move Instructions
- 3.5.4 Copy and Conversion Instructions
- 3.5.5 Shift Instructions
- 3.5.6 Compare Instructions
- 3.5.7 Floating Point Arithmetic Instructions
- 3.5.8 Integer Arithmetic Instructions
- 3.5.9 Accumulator Arithmetic Instructions
- Boot ROM
- System Controller
- Vectored Interrupt Controller
- 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
- 7.4.1 VILOSATI (Video Image Line Output Scanner and Transfer Interface)
- 7.4.2 Video FIFO
- 7.4.3 Video Pixel MUX
- 7.4.4 Blink Function
- 7.4.5 Color Look-Up-Tables
- 7.4.6 Color RGB Mux
- 7.4.7 Pixel Shift Logic
- 7.4.8 Grayscale/Color Generator for Monochrome/Passive Low Color Displays
- 7.4.9 Hardware Cursor
- 7.4.10 Video Timing
- 7.4.11 Blink Logic
- 7.4.12 Color Mode Definition
- 7.5 Registers
- Graphics Accelerator
- 1/10/100 Mbps Ethernet LAN Controller
- 9.1 Introduction
- 9.2 Descriptor Processor
- 9.2.1 Receive Descriptor Processor Queues
- 9.2.2 Receive Descriptor Queue
- 9.2.3 Receive Status Queue
- 9.2.3.1 Receive Status Format
- 9.2.3.2 Receive Flow
- 9.2.3.3 Receive Errors
- 9.2.3.4 Receive Descriptor Data/Status Flow
- 9.2.3.5 Receive Descriptor Example
- 9.2.3.6 Receive Frame Pre-Processing
- 9.2.3.7 Transmit Descriptor Processor Queues
- 9.2.3.8 Transmit Descriptor Queue
- 9.2.3.9 Transmit Descriptor Format
- 9.2.3.10 Transmit Status Queue
- 9.2.3.11 Transmit Status Format
- 9.2.3.12 Transmit Flow
- 9.2.3.13 Transmit Errors
- 9.2.3.14 Transmit Descriptor Data/Status Flow
- 9.2.4 Interrupts
- 9.2.5 Initialization
- 9.3 Registers
- DMA Controller
- 10.1 Introduction
- 10.1.1 DMA Features List
- 10.1.2 Managing Data Transfers Using a DMA Channel
- 10.1.3 DMA Operations
- 10.1.4 Internal M2P or P2M AHB Master Interface Functional Description
- 10.1.5 M2M AHB Master Interface Functional Description
- 10.1.6 AHB Slave Interface Limitations
- 10.1.7 Interrupt Interface
- 10.1.8 Internal M2P/P2M Data Unpacker/Packer Functional Description
- 10.1.9 Internal M2P/P2M DMA Functional Description
- 10.1.10 M2M DMA Functional Description
- 10.1.11 DMA Data Transfer Size Determination
- 10.1.12 Buffer Descriptors
- 10.1.13 Bus Arbitration
- 10.2 Registers
- 10.1 Introduction
- Universal Serial Bus Host Controller
- Static Memory Controller
- SDRAM, SyncROM, and SyncFLASH Controller
- UART1 With HDLC and Modem Control Signals
- UART2
- UART3 With HDLC Encoder
- IrDA
- Timers
- Watchdog Timer
- Real Time Clock With Software Trim
- I2S Controller
- AC’97 Controller
- Synchronous Serial Port
- 23.1 Introduction
- 23.2 Features
- 23.3 SSP Functionality
- 23.4 SSP Pin Multiplex
- 23.5 Configuring the SSP
- 23.5.1 Enabling SSP Operation
- 23.5.2 Master/Slave Mode
- 23.5.3 Serial Bit Rate Generation
- 23.5.4 Frame Format
- 23.5.5 Texas Instruments® Synchronous Serial Frame Format
- 23.5.6 Motorola® SPI Frame Format
- 23.5.7 Motorola SPI Format with SPO=0, SPH=0
- 23.5.8 Motorola SPI Format with SPO=0, SPH=1
- 23.5.9 Motorola SPI Format with SPO=1, SPH=0
- 23.5.10 Motorola SPI Format with SPO=1, SPH=1
- 23.5.11 National Semiconductor® Microwire™ Frame Format
- 23.6 Registers
- Pulse Width Modulator
- Analog Touch Screen Interface
- 25.1 Introduction
- 25.2 Touch Screen Controller Operation
- 25.2.1 Touch Screen Scanning: Four-wire and Eight-wire Operation
- 25.2.2 Five-wire and Seven-wire Operation
- 25.2.3 Direct Operation
- 25.2.4 Measuring Analog Input with the Touch Screen Controls Disabled
- 25.2.5 Measuring Touch Screen Resistance
- 25.2.6 Polled and Interrupt-Driven Modes
- 25.2.7 Touch Screen Package Dependency
- 25.3 Registers
- Keypad Interface
- IDE Interface
- GPIO Interface
- Security
- Glossary
- EP93XX Register List

25-10 DS785UM1
Copyright 2007 Cirrus Logic
Analog Touch Screen Interface
EP93xx User’s Guide
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25
The algorithm then would continue by discharging and detecting a valid touch. With no X
interrupt pending flag, the algorithm also continues by discharging and detecting a valid
touch, but without interrupt generation. If the difference between the new Y value and the last
Y value is greater than the YMIN value, the algorithm continues by comparing the difference
between the new Y value and the last Y value to the YMAX value in the TSXYMaxMin
register. If the difference is greater than YMAX, it is assumed that this distance is too far for a
touch input to possibly move in the short scan time interval and that the key press is invalid.
However, it is stored as the last recorded Y location in case a truly new location is being
determined (that is, no contact to contact or contact to no contact).
The Y move interrupt pending flag is also set at this point to cause the algorithm to skip over
the comparison to YMIN on consecutive sample sets. This flag will also cause an ARM Core
interrupt as soon as a valid Y sample can be established. The algorithm then starts over
discharging and detecting a valid press. If the difference between the new Y value and the
last stored Y value is less than the YMAX value, the algorithm stores the new Y value in the Y
last register, and the stored X value is moved to the X last register. The interrupt to the ARM
Core is generated, and the algorithm continues by moving to the settle state and detecting a
valid press. The interrupt is cleared when the TSXYResult register is read or by clearing the
TSSetup2.TINT bit.
As can be seen from Figure 25-3, 4-wire touch screens are operated in much the same way a
8-wire touch screens, except that the reference for the A / D converter is internal instead of a
feedback. The register values TSDetect, TSDischarge, TSXSample, and TSYSample are
derived from the switch positions in the diagram. They are documented in Table 25-2.
25.2.2 Five-wire and Seven-wire Operation
Five-wire touch screens require a different connection scheme than 4- or 8-wire touch
screens. The X+ and X- lines become static V+ and V- lines. The Y+ and Y- lines are Z+/- and
Z-/+ and are used to switch between X and Y axis. The reference for the A / D converter is
internal. One of the feedback lines, for example, sY+ is used as a Wiper input to the A / D
converter. The register values TSDetect, TSDischarge, TSXSample, and TSYSample are
derived from the switch positions in the diagram. They are provided in Table 25-2.
Seven-wire touch screens (5-wires with feedback) are very similar to a normal 5-wire touch
screen, except that the A / D reference is taken from the external circuit. The X+ and X- lines
are still static V+ and V-lines. The Y+ and Y- lines are still Z+/- and Z-/+ and are used to
switch between X and Y axis. However, the reference for the A / D converter is on the sX+
and sX- lines relabelled as sV+ and sV-. The sY+ feedback line is still used as a Wiper input
to the A / D converter.
The register values TSDischarge, TSXSample, and TSYSample are derived from the switch
positions in the diagram. They are provided in Table 25-2.