Dopplex Vascular Assist Service Manual

Table of Contents

HEALTHCARE

Contents

Page No.

1. General Information...4 1.1 1.2 1.3 1.4 1.5 1.6 1.7

Introduction...4 System Components...4 Servicing Policy...5 Acoustic Safety...6 Product Description...7 Antistatic Handling, Electro Static Discharge (ESD)...8 Construction...8

2. Quality, Reliability and Safety...9 2.1 2.2 2.3 2.4 2.5 2.6 2.7

General Safety...9 Safety Testing...10 Power Adaptor...10 Assist Host and Docking Station...10 Cleaning...11 Preventative Maintenance...11 CE Marking...11

3. Specifications...12 3.1 3.2 3.3 3.4 3.5

EN60601-1 Classification...12 General...12 Environmental...12 Physical...13 Sensors...13

4. Technical Classification...14 4.1 4.2

The Doppler Principle...14 Doppler Audio Processing...14

5. Main PCB Circuit Description...15

2

5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.7.1 5.8 5.9 5.10 5.11 5.12 5.13 5.14 5.15 5.16 5.17 5.18 5.19 5.20 5.21 5.22 5.23 5.24 5.25

Introduction...15 Overview of Circuit Functionality...15 The AMD SC400 Micro Controller...15 CPU Clocks...15 ROM / FLASH Interface...15 DRAM Controller...16 SC400 Functions Used by the PMA Main PCB...16 PC Card Socket 1 (PCMCIA Port)...17 Flash Memory...17 Battery Level Comparator...17 On/Off Detect CIrcuit...17 Clock Ladder...18 Docking Power and Detect Circuit...18 VR Micro Controller...18 Dual Port RAM Interface...19 Ultra I/O...19 Parallel Port...19 Serial Port...20 32KHz Oscillator...20 RESET and Watchdog Circuit...20 Graphics Controller...21 Memory Addressing...21 Contrast and Brightness Control...21 Touch Screen Control...22 Key Pad Interface...22 Touch Screen Controller...22

Contents

Page No.

6. Vascular Assist Overview...23 6.1 6.2

Signal Processing...25 PPG Daughter PCB...26

7. Docking Station...27 7.1 7.2

Desktop Operation - Power fed through the Docking Station...27 Docking Station Block Diagram...28

8. Mains Adaptor / Battery Pack Specification...29 8.1 8.1.1 8.1.2 8.1.3 8.1.4 8.1.5 8.1.6 8.1.7 8.2 8.2.1 8.2.2 8.2.3 8.2.4

Mains Adaptor...29 Introduction...29 Mains Input...29 DC Output...29 Safety Isolation...29 Operating Environment...29 Storage Environment...30 Electromagnetic Compatibility...30 Battery Pack...30 Introduction...30 Cell Type...31 Battery Discharge...31 Desktop Operation - Power fed through the Battery Pack...31

Table of Contents

HEALTHCARE

9. Electrostatic Discharge (ESD) Precautions...32 9.1

What is Static Electricity?...32

10. Servicing Procedures...33 10.1 10.2 10.3 10.4 10.5 10.6 10.7

Unit Dismantling...33 Removal of Host PCB...33 Removal of Touch Screen & LCD Module...34 Invertor PCB Removal...34 Speaker Removal...34 Removal of the Keypad...34 Vascular Module...34

11. Ordering Spare Parts...35 12. Fault Finding...36 13. Modular Diagrams...39 14. Probe Assemblies...48 14.1 14.2 14.3

AVT4 and AVT8 Transducers...48 APPG1 Sensor...51 VPPG1 Sensor...52

15. Vascular Functional Inspection & Test Procedure...53 15.1 15.2

Soak Test...53 Post Soak Procedure...53

16. Field Software Upgrades for Vascular Assist...61 17. Warranty and Service...62 Pages from User Manual...63

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Product Description

HEALTHCARE

1. General Information Alth hough h every y care has been tak ken to ensure th hat th he information in th his manual is accurate, continuous development may y result in equipment ch hanges.. The Company y reserves th he righ ht to mak ke such h ch hanges with hout prior notification, and resulting manual inaccuracies may y occur.. This manual and any y ch hanges are protected by y copy yrigh ht..

1.1

Introduction The Dopplex Assist product range is designed to give the user maximum flexibility to carry out clinical assessments anywhere within the hospital, in the community or even in the patients’ home. The core microprocessor based Host unit accepts characterising Modules so that the Dopplex Assist becomes either a Vascular Laboratory, (Vascular Assist), an Antenatal Fetal Monitor, (Fetal Assist), or a Cordflow Monitor, (Cordflow Assist).

1.2

System Components The Dopplex Assist is modular in format, requiring that several components are assembled before a particular procedure can be undertaken.

Host Unit

This is a handheld core system powered from rechargeable batteries, or via a mains adaptor. It includes a graphic display and connectivity and data storage/management.

Application Module

This is a rectangular ‘box’, (approx. 180* 140* 20mm), which contains all the necessary electronics and software to perform the specified function.

Patient Applied Parts (Transducers)

These items produce the signals that are analysed by the Dopplex Assist system. They plug into the Module via 9 pin connectors.

Battery Pack

The batteries are housed in a unit that fits into the Host. The design of the case is such that the Battery Pack can only be inserted in one way.

Power Adaptor

This unit allows the Host/Module combination to be powered from mains electricity supply. The batteries can also be recharged from the output of this unit, during, or independent of, patient assessments. The output is regulated, and the complete power adaptor meets the safety requirements of EN60601-1. The output of the power adaptor is fitted with a unique connector that is specific for use with the Dopplex Assist system.

Docking Station

4

This accessory allows the Host/Module combination, (together with the battery pack), to be used as a desktop unit. The unit is held at a convenient angle for viewing the displayed results. The preferred option is for the power adaptor to be connected to the Docking Station. In this configuration, an external printer and audio speakers are available.

Host Unit Several elements are brought together in this unit. They are described below: Element

Location

Function

Touch Screen

Front Face

Displays information useful to the clinician such as patient information, results of procedures etc.

Membrane Keypad

Front Face

Can be used to input information in addition to using the Touch Screen.

Headphone and Serial Port Sockets

Right Hand Edge

A headphone socket is provided for the clinician to listen to procedures if required. A mono loudspeaker is also included for audio presentations. A serial input/output port for connection to an external keyboard or mouse is also provided.

PCMCIA Port

Top Edge

This permits connection from an external telephone/LAN network to be made to the Dopplex Assist so that information gathered can be downloaded to a central location. The Fax/modem cards are manufactured to comply with EN60950.

Smart Card Reader

Right Hand Edge

For the indirect entry of patient data.

IrDA Port

Right Hand Edge

Provides wireless printing capability. (Not available at present).

Product Description

HEALTHCARE

Note: There are 2 banks of contacts which are exposed when in handheld operation. These contacts are to establish connectivity between the Host and Docking Station, and are not energised during handling operation.

1.3

Servicing Policy Due to the nature of static-sensitive surface-mount technology, specialised equipment and training is required when working on the surface mounted components used within this product. For this reason, circuit diagrams are not included in this manual. Block diagrams and fault finding sections are included to make fault finding to modular or leaded component level possible. Units within the warranty period must not be dismantled and should be returned to Huntleigh Healthcare, Diagnostic Products Division for repair. Any units returned showing signs of tampering or accidental damage will not be covered under the warranty.

Caution! To reduce the risk of electric shock, do not remove the cover or back. Refer servicing to qualified service personnel. Only trained service technicians should perform all unit repairs. Voltages dangerous to life exist in this unit. Take care when servicing the power supply and display assembly.

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Product Description

HEALTHCARE

1.4

Acoustic Safety Continuous wave Doppler ultrasound instruments such as the ASSIST have been used extensively for medical diagnosis in the United States for over 25 years. Throughout this period, there have been no reports of adverse effects to patients or instrument operators at the acoustic intensities recommended for diagnostic use. Despite this highly favourable safety experience, available data are not conclusive and the possibility remains that unwanted biological effects might be identified in the future. Authorities therefore recommend that ultrasound procedures be performed in accordance with the "ALARA" principle, which states that the energy delivered to the patient should always be kept As Low As Reasonably Achievable. With the ASSIST RANGE, the transmitted acoustic power is fixed and cannot be adjusted by the operator. Therefore, the user can best observe the ALARA principle by ensuring that each examination is medically indicated and by limiting the duration of the study to the extent appropriate for the clinical objectives. Acoustic intensity data (ISPTA.3) for the probe available for use with the VASCULAR and DOPPLER ASSIST is summarised in the table below. The values cited are based on measurements in water using a calibrated hydrophone and are stated as the estimated derated intensities. The derated intensity constitutes the most biologically relevant parameter available since true determinations of the actual absorbed dose in tissue would require invasive measurement techniques. The derated intensity is, therefore, calculated mathematically using a derating factor consisting of a constant (the assumed attenuation coefficient) and allowing for the frequency of the probe and the distance from the probe face to the hydrophone. The calculated derated intensity values for the ASSIST RANGE compare very favourably with previously reported acoustic safety data for Doppler ultrasound instruments and are appropriate for all clinical applications recommended in this manual.

Acoustic Output Reporting Table for Track 1 - Non-Auto-scanning Mode Operating Mode: CW-Mode Application(s): Vascular Monitoring Transducer Model: AVT4 Acoustic Output

Maximum Value Pr.3 (Mpa)

MI

Associated Acoustic Parameters

Isppa.3

(mW/cm2)

(mW/cm2

0.030 86.2 0.636

Wo (mW)

N/A

MI

Ispta.3

Isppa.3

(mW/cm2)

(mW/cm2

0.023 87.6 0.746

8.2

5.2

fc (MHz)

4.0

4.0

8.0

Zsp (cm)

8.0

8.0

4.8

Beam

x-6 (cm)

0.365

0.215

Dimensions

y-6 (cm)

0.8

0.5

PD (µS)

N/A

N/A

PRF (Hz)

N/A

N/A

EBD (cm2)

6

Ispta.3

Transducer Model: AVT8

0.12

0.026

N/A

Notes 1

Measurement uncertainty

2

Wo (mW)

Pr.3 (Mpa)

Ispta. (mW/cm2)

fc (MHz)

25.8%

13.5%

25.4%

5%

Intended uses: refer to the Recommended Clinical Applications section.

Definition of Terms

1.5

ISPTA.3

the derated spatial-peak temporal-average intensity (milliwatts per square centimetre).

ISPPA.3

the derated spatial-peak pulse-average intensity (watts per square centimetre).

MI

the Mechanical Index.

Pr.3

the derated peak rarefactional pressure (megapascals).

Wo

the ultrasonic power (milliwatts).

fc

is the centre frequency (Megahertz)

Zsp

is the axial distance at which the reported parameter is measured (centimetres).

X-6, Y-6

are respectively the in-plane (azimuthal) and out-of-plane (elevational) -6dB dimensions in the x-y plane where zsp is found (centimetres).

PD

the pulse duration (microseconds).

PRF

the pulse repetition frequency (Hz).

EBD

the entrance beam dimensions for the azimuthal and elevational planes (centimetres).

Product Description

HEALTHCARE

Product Description The Dopplex Assist range of modular systems is designed to fulfil a multitude of application areas using a single 'host' unit and selecting the relevant module to provide the required functionality. The host unit comprises High resolution ½ VGA colour graphic display complete with touch screen for data entry Internal rechargeable battery providing up to 4 hours use Internal memory for storage of patient record PCMIA slot for expansion of memory or addition of modem/network card Smartcard reader allowing direct patient data entry

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Product Description

HEALTHCARE

Vascular Module By fitting the vascular module, the Assist becomes a handheld vascular assessment unit incorporating colour spectrum analysis utilising a selection of ultrasound transducers, PPG (arterial or venous up to two two channels) and blood pressure measurement. Doppler probes incorporate a zero force switch allows recording and saving of traces to be simplified. The Vascular Assist can also be connected to a colour printer to allow high quality printouts of the vascular test.

1.6

Antistatic Handling, Electro Static Discharge (ESD) The Vascular Assist range use Electrostatic Discharge Sensitive Devices (ESD's) in its manufacture. The damage they suffer when handled incorrectly may be catastrophic. More often and potentially even worse, the damage may be partial or latent, seriously impairing the reliability of the unit. Due to the nature of the components used within the Assist, special precautions must be taken to avoid damage to the circuitry. Static damage may not be immediately evident but could cause premature failure. The Assist must only be dismantled and serviced within an ESD protected area (EPA) as defined by CECC00015 (published by CENELEC) to avoid damage to the assemblies.

1.7

Construction The Host unit comprises five PCB's, the main PCB, docking station connector, Smartcard reader, bulkhead and LCD backlight PCB's. The vascular module consists of two PCB's, a main and daughter PCB. The PPG probes are sealed, while the vascular ultrasound transducers consist of one main and a switch PCB. All electromechanical and through hole components are serviceable using standard tools and soldering techniques, provided that anti-static precautions are always taken. Recommended servicing is limited to replacement of assemblies detailed in this manual.

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2. Quality Reliability and Safety 2.1

General Safety This equipment has been manufactured using quality y components and designed to operate safely y and with h reliability y. Huntleigh h Health hcare Limited can accept responsibility y only y if th he follow wing conditions are observed.. The equipment is used in accordance with h th he instructions for use provided by y Huntleigh h Health hcare.. The equipment is used in a building whose electrical installations conform to th he standards specified by y th he country y in which h th he building is situated.. If th he integrity y of th he protective earth h conductor arrangement is in doubt, th he equipment sh hould be operated from its internal electrical pow wer source.. All modifications and repairs to th he equipment are carried out by y service engineers, agents or hospital tech hnicians auth horised by y Huntleigh h Health hcare Limited.. "T The Vascular Assist and its transducers are designed to high h standards of performance, reliability y and safety y. Functional and safety y ch heck ks sh hould alw way ys be made after carry ying out any y repairs or dismantling th he equipment..

Quality Reliability and Safety

HEALTHCARE

It is recommended th hat regular inspections are to be made to ch heck k th he integrity y of th he unit, and to ensure cables are not sh how wing any y signs of wear or noise when flexed..

Note

The following are descriptions of general hazards and unsafe practices that could result in death, severe injury or product damage. Specific warnings and cautions not appearing in this section are found throughout the manual.

Possible Fire or Explosion

A possible explosion hazard exists if used in the presence of flammable anaesthetics. Explosion or fire can result.

Possible Electrical Hazard

Do not operate the equipment using damaged cables and wires, or loose snap fittings, which may cause interference or loss of signal. Do perform frequent electrical and visual inspections on cables and wires.

Possible Equipment Damage

Do not immerse any portion of the instrument in water. Fluid spills may damage the instrument's electrical components. Do not sterilise this product. Sterilisation environments can cause severe damage. Do not autoclave or gas sterilise accessories unless manufacturer instructions clearly approve it.

Possible Safety Risk

Do not substitute accessories. Use only recommended accessories listed in this manual. Substitution may cause the instrument to work improperly. The correct accessories are shielded to prevent conductive parts of the electrodes contacting other conductive parts or earth.

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Quality Reliability and Safety

HEALTHCARE

Do not use this equipment in the presence of flammable gases. Do not immerse any part of the equipment in any liquids. Do not use solvent cleaner on any part of the system. Do not use high temperature sterilising or E-beam / gamma sterilisation processes.

This product contains sensitive electronics; strong radio frequency fields could interfere with the operation of the system. In the event where this occurs, we suggest that the source of interference is identified and the equipment is used 'out of range'.

If any y doubt exists concerning th he use of th his equipment, an alternative meth hod sh hould be used..

2.2

Safety Testing Using suitable safety test equipment, refer to the following guidelines;

2.3

Power Adaptor

Earth Leakage Test Maximum allowable leakage current :

100 µA Limit

Enclosure Leakage Current :

100 µA Limit

Insulation Test Mains to Case :

> 200 M

Breakdown Test Apply 1500Vac to the mains connector, connecting the low voltage probe to the "EARTH" terminal. Firstly test the "LIVE" terminal and then the "NEUTRAL" for 60 seconds each. No breakdown should occur. The output from the power adaptor is double insulated from its supply. The third pin from the adaptor is earthed but this is a functional earth and not a safety earth.

2.4

Assist Host and Docking Station Due to the fact that these are powered from an isolated supply, testing of these units is not necessary. If you require any assistance with safety testing your Huntleigh Diagnostics equipment, contact Huntleigh Diagnostics. For the UK refer to the Health Equipment Information Document No 95 Code Of Practice or IEC 601 Standards For Acceptance Testing Of Medical Equipment. The following safety summary should be read before operating or carrying out any of the procedures described in this manual:

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2.5

Cleaning Ensure th he sy ystem is sw witch hed off and disconnected from th he mains supply y.

Main Unit / Screen

If required, this can be wiped with a soft cloth dampened with a mild detergent, avoiding the connectors. Do not allow any fluid to seep into the connectors. Do not allow any fluid to seep into the unit. Ensure the unit is completely dry before reconnecting to the mains.

Do NOT T immerse connectors

Transducers Only. To assist with disinfection, wipe the transducers with a soft cloth dampened with sodium hypochlorite 1000ppm, and wipe dry. Please be sure to check your local infection control policies or equipment cleaning procedures.

Disinfection

Check your local infection control policies or equipment cleaning procedures.

Quality Reliability and Safety

HEALTHCARE

Caution Ph henolic, detergent based disinfectants containing cationic surfactants, ammonia based compounds, or antiseptic solutions such h as Steriscol or Hibiscrub sh hould never be used on any y part of th he sy ystem as permanent damage will result..

2.6

Preventative Maintenance The Huntleigh Diagnostics Vascular Assist is designed for a minimum amount of maintenance. To support the high standard of performance and safety, the safety and functional checks should be carried out as part of a regular maintenance routine.

Periodic inspection and preventative maintenance are essential to ensure continued effective operation.. Contact th he Company y or its approved agents or distributors for furth her information on service contracts.. Refer to the user manual for details of connection of cables and accessories, and also for the correct setting of controls which may have been altered during maintenance.

No attempt should be made to service the unit unless adequate workshop facilities and suitable technical staff are available.

2.7

CE marking This equipment carries a CE mark but this is only fully valid if it is used in conjunction with cables and other accessories approved by Huntleigh Healthcare Limited. All rework procedures detailed in this service manual must be strictly adhered to, to ensure continuing compliance with EC Directive 93/42/EEC. Any rework routine carried out outside the scope of this manual may result in the equipment no longer meeting this specification and the rework organisation will be responsible for this nonconformance.

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Specifications

HEALTHCARE

3. Specifications 3.1

Type of protection against electric shock.

3.2

3.3

12

EN60601-1 classification

Class 1 (when operated via the supplied PSU) / internally powered.

Degree of protection against electric shock

Type B applied part

Mode of operation.

Continuous

Degree of protection against water ingress

IPX0

Degree of Safety in Presence of Flammable Gases:

Not suitable for use in the presence of flammable gases.

General

Regulatory y Compliance

Complies with:

Electrical Probe Frequencies

AVT4 4.0MHz ± 1% AVT8 8.0MHz ± 1%

Effective area of transmitter element:

AVT4 22mm² AVT8 8mm²

BP Input

Range: Precision:

Gel

Type: Viscous aqueous non-sensitising, hypo allergenic / non irritating.

EN60601-1: 1990; UL2601-1

EN60601-1-2 : 1993

0 - 300mmHg ± 5mmHg

Environmental Operating Temperature

+10°C to +30°C

Storage Temperature

-10°C to +40°C

Relative Humidity y

90% (non condensing)

Atmosph heric Pressure

700mb - 1060mb

3.4

Physical

Module

System m 2" (50mm) x 10" (250mm) x 6" (150mm)

Size (HxWxD)

3.5 lb (1.6Kg) (including battery)

Weigh ht

¾" (18mm) x 7" (175mm) x 5.4" (135mm) 2 ½ oz. (325g)

Specifications

HEALTHCARE

Dockin ng Station n Size (HxWxD)

3.5

5" (127mm) x 11" (279mm) x 10.2" (258mm)

Sensors

APPG Sen nsor

VPPG Sen nsor 950nm ± 20nm 27mm Dia x 10mm deep. 1.75m 7g

Wavelength h

950nm ± 20nm

Size

62 x 25 x 25mm

Cable Length h

1.75m

Weigh ht

40g

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4. Technical Description 4.1

The Doppler Principle The Vascular Assist uses the Doppler principle for non-invasively monitoring movement within the body. The Doppler principle states that if a signal is transmitted at a fixed frequency and is reflected by a moving body, the frequency of the received signal will be shifted. An increase in frequency results if the reflector is moving towards the transmitter/receiver, and a decrease results if moving away from the transmitter/receiver. The amount of frequency shift is proportional to the velocity of the reflector relative to the transmitter/receiver. In the Dopplex range, a fixed frequency ultrasonic signal is transmitted from the transducer into the body. This is reflected from, for example, a blood flow. The signal is reflected from the blood flow and is received by the transducer. Due to this movement, a frequency shift results, which is proportional to this flow velocity.

Ultrasound Transducer - 4MHz

Vascular Module ASIC - FFT Interface to Host

H8 Processor

Pressure Analogue Analogue Measure Processing Processing

Technical Description

HEALTHCARE

Please Note: All transducers are interchangeable.

Ultrasound Transducer - 8MHz Arterial PPG Transducer Venous PPG Transducer Manual BP Bulb

BP Cuff 4.2

Doppler Audio Processing The Dopplex Assist ultrasound transducer contains a transmitter and receiver. In use, the transducer sends out a pulsed ultrasonic signal, generated by the piezo-ceramic transmitter crystals. This signal is scattered by blood cells or any other "interface" such as skin, muscle layers, organs, walls of vessels etc. A small proportion of the scattered signal will be reflected back and detected by the receiver.

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By demodulating the received signal (removing the high frequency carrier) the Doppler shifted component (i.e. the difference between the transmitted and received signals) can be produced. With typical target velocities found in the human body, this Doppler shift signal falls within the audio frequency range. It can therefore simply be amplified and heard through a loudspeaker. It is important to remember that the sound you hear is an artificial sound, the frequency (pitch) of which is proportional to the velocity of the moving target.

5. Main PCB Circuit Description 5.1

Introduction The PMA Host’s main PCB is a PC-based single board computer that uses the AMD ELAN SC400 as its main processor. It is used as part of hand held multi-purpose medical devices. The board is to be used to record, display and communicate medical data that has been preprocessed by a connected module. The connected module will determine the nature and functionality of the complete device.

5.2

Overview of Circuit Functionality The overall circuit is controlled by the ELAN SC400; a single chip embedded 486-based microcontroller. Additional functionality has been added externally to this chip in the form of Ultra I/O, Display controller, touch screen controller, Power supplies, DRAM, Flash memory, EPROM, Dual port ram, external micro-controller, reset circuitry, Audio amplifier and various support circuitry. The circuit supports various operating systems including, QNX, Windows95, MSDOS etc.

5.3

The AMD SC400 Micro Controller The Elan SC400 is a 32 bit low voltage (2.7V -3.3V) AM486 CPU with a complete set of PC/AT compatible peripherals, and in addition, power management features for increased battery life. The Elan SC400 uses the industry standard 486 instruction set; therefore software written for x86 architecture is compatible with the ELAN SC400 micro-controller.

Main PCB Circuit Description

HEALTHCARE

The AM486 CPU core, which is of a fully static design that, can be operated at frequencies up to 100MHz. It also contains an 8Kbyte write-back cache for enhanced performance by reducing bus traffic. The ELAN SC400 has internal configuration registers that are used to configure the microcontrollers internal features. These registers use a pointer index scheme and most can be accessed writing the register index to I/O port 22h and then reading or writing data to I/O port 23h.

5.4

CPU Clocks The Elan SC400 uses an on chip crystal oscillator circuit that requires only one external 32KHz crystal connected to X32IN and X32OUT pins. This is used to generate all other clock frequencies, needed by the micro-controller. This is done by the use of four Phase-locked loop circuits with dedicated external loop filters, consisting of two capacitors and a resistor.

5.5

ROM/FLASH Interface The micro-controller has three glue-less burst-mode ROM/FLASH active low chip selects, that allows a mixture of ROM and FLASH memory to be added with no external control logic. Each chip select area can be individually configured to use 8/16/32bit ROM/FLASH devices up to 64Mbytes. These areas may be individually write-protected to protect code in flash devices. ROMCS0# and ROMCS1# have direct mapping to external pins, unlike ROMCS2# which has to be redirected to any of the GPIO_CS 0-14 pins. The PMA uses ROMCS0# as the EPROM area and ROMCS1# and ROMCS2# as FLASH memory banks.

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Main PCB Circuit Description

HEALTHCARE

5.6

DRAM Controller The SC400 has an integrated DRAM controller that provides all the signals necessary to support DRAM's gluelessly. Internal registers are provided to select the type, operating mode and refresh rate. It supports the following features: 3.3V Fast page mode or EDO 70ns DRAM's Extended and self refresh modes Page mode reads and writes Symmetrical and asymmetrical DRAM support

5.7

SC400 Functions Used by the PMA Main PCB The PMA circuit uses the following functions in its design: Internal DMA control is available only. Uses 7 of the eight external interrupts (PIRQ1-7) Internal programmable interval timers are all available. The internal Real Time Clock is used. The PC/AT support features including speaker output. The serial port and IrDA port are both available for use but only one can be used at any one time. (The SC400 serial port is the systems COM1 at address 3F8h. It is used as the docking station/module programming serial port and is 5V TTL level only) PCCARD socket one is used only. GPIO's are used where available. The boundary scan interface is available to use for test purposes only. VESA-Local bus is being used ISA bus is being used DRAM interface is being used. Graphics interface Parallel port. Keypad matrix support External DMA External interrupt PIRQ0 PC Card-socket 2.

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5.7.1PC-Card Socket 1 (PCMCIA port) The SC400's integrated PC-Card controller is PCMCIA2.1 compliant. Although capable of supporting two card sockets, this circuit only utilises one socket and uses the extra pins as GPIO ports. The socket is capable of DMA transfer from PC-Card to system DRAM. The PCMCIA card socket is to be used for the addition of extra memory with the use of SRAM or FLASH memory cards; it is also to support "Psion Gold Card" modems in order to transmit data over a telephone line or the Internet. In addition to this the socket card be used to boot the system when used in conjunction with the configuration pins described above. This will allow the programming of the on board flash array from the PC-Card socket.

5.8

FLASH Memory The PCB contains a flash memory array that can take that consists of 4 x 2Mbyte or 4 x 4Mbyte AMD flash memory. This gives a total of 8/16Mbytes of flash that is used as a solid state disk. It is to be used as a storage medium for the QNX image, temporary storage of the application software and user files etc. The FLASH memory is a form of EEPROM that contains embedded algorithms to erase and program the internal memory. As well as being able to read internal status registers, for the current status of the flash memory, there is an external RDY/BSY# line. This gives a hardware indication of whether the flash memory is busy erasing/programming the flash array, or ready for the next command. There is also an external reset pin that puts the flash memory into read access mode.

Main PCB Circuit Description

HEALTHCARE

The flash memory is arranged in either 32x or 64x, 64K sectors, depending on which device is fitted. These sectors can be individually or group erased, or the whole chip can be erase at once. (Individual address can not be erased).

5.9

Battery Level Comparator The MAX924 (U36) is a quad comparator circuit for monitoring the battery voltage level so the SC400 can implement hardware power management features. It is powered from the 3.3V power supply rail in order not to overpower the battery level inputs of the SC400. The device outputs a 1.182V reference, which is produced by an internal band-gap reference diode. This is then potentially divided to produce the four reference levels for the four comparators. These reference levels for the negative inputs of the four comparators are A = 1.047V, B = 997mV, C = 818mVand D = 798mV. A proportion (0.116 * battery voltage) of the battery level is then feed to the positive inputs of these comparators. When the positive input falls below a comparators negative input reference the output of that comparator goes logic low (0V). As a comparators positive input increases above the negative input reference the output of that particular comparator goes high (3.3V). These comparators produce logic low output levels for the following battery voltage levels. A = 9.05V, B = 8.62V, C = 7.07V and D = 6.9V.

5.10 On/Off Detect Circuit When the on/off button is pressed on the front panel the raw battery voltage is fed to the base of Q5 via the diode D24 and the R96, R93 potential divider this turns the transistor on and pulls the gates of a dual FET (U42) to ground. This switches the FET (U42) on switching the battery voltage through to the power supplies. Once out of reset the sc400 micro-controller holds the CPU_ON_HOLD signal high, this in turn holds the transistor Q5 on via the second diode in D24. When the on/off button is pressed the Transistor Q6 is switched on sending a low-level pulse to the micro-controllers CPU_ON_OFF_DETECT input. When the button is not being pressed the transistor Q6 is off holding the CPU_ON_OFF_DETECT high (3.3V). (Note the transistor is not activated when the CPU_ON_HOLD signal is active because of the reversed biased diode.) When the SC400 micro-controller receives the CPU_ON_OFF_DETECT low signal it should proceed to power down and release the CPU_ON_HOLD signal. This in turn will switch off transistor Q5 and the Gates of U42 are pulled high via R117 to switch of the FET (U42), thus removing the power from the power supplies.

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Main PCB Circuit Description

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5.11 Clock Ladder A 7.3728MHz crystal (XM2 or X3 which ever is fitted) is used to produce 3 of the PCB's clock frequencies. They are divided down using to d-type flip-flops to produce 3.6864MHz for the AVR micro-controller and CODEC circuit, and 1.8432MHz for the touch screen controller. The master 7.3728Mhz clock signal is for the A/D converter of the CODEC circuit. This clock ladder can be switched on/off via the 1.8MHz_OFF# signal. The resistor R100 and capacitor C136 filter the clock signal to reduce EMC emissions from this source.

5.12 Docking Power and Detect Circuit The power from the docking station comes in on the contacts JP14, JP15 this is then fed to the battery via the diode (D35). D35 also prevents false triggering of the docking detect signal when the power supply is plugged in to the battery. When power is present between the contacts JP14, JP15 this turns on the transistor Q10, which in turn pulls the DOCKED# signal low, signalling to the rest of the circuit the docking station is present. When no power is connected to JP14, JP15 the transistor is off and the signal can be pulled high signalling the docking station is not present.

5.13 VR Micro-controller The AVR (U39) is an 8bit micro-controller its main job is to release the SC400 from slow, time intensive, single line communication protocols. It communicates with the battery gas gauge IC (in the battery pack) via a single line protocol at a maximum bit rate of 333bit/s. The AVR also communicates with a temperature sensor (U54) via a one-wire protocol. The data from these two sources is then transmitted via UART at a 9600baud rate, to the SC400 on COM3 (this is UART 2 on the Ultra I/O.) The AVR also monitors the battery voltage level via an internal comparator circuit. The reference for this comparator is set at 2.2V via the potential divider (R84, R81) across the 3.3V supply. The battery voltage level is then potentially divided (by R95, R99 to give battery voltage * 0.166). If the battery voltage is more than 13.2V it triggers the internal comparator. This comparator output used in conjunction with the charge status bit of the gas gauge can then be used to detect whether a power supply is present. The result of this monitoring means that the ACPWR pin can be used to indicate there is a power supply plug in to the SC400 power management inputs. The temperature sensor (U54) is used to measure the temperature of the unit in order to compensate for contrast and brightness drift due to temperature. This device can be programmed to convert the temperature in a 9-12bit resolution over the range -55ºC to 125ºC. The temperature sensor has a 64 bit unique serial number that can also be used to identify the PCB. The communication with this device is through a 1-wire serial interface. Provision has been provided that the AVR software can be updated via the SC400 application software. This is done via the integral SPI interface and holding the AVR in reset. The AVR is clocked from the 3.6864MHz clock this is a baud rate frequency clock that produces 0% error in UART baud rate. The inverters U40C-F are used to convert the 3.3V signals to 5V signals for the ULTRA I/O chip. The AVR also illuminates the power on LED on the front panel this is so the LED can be 'immediately' turned on as power is applied it also allows for future LED flashing to indicate suspend mode.

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5.14 Dual Port RAM Interface The dual port RAM is the main communication interface between the host unit and the module. It consists of an 8K x 8 static RAM and two-access ports to permit independent high speed, read and writes to the RAM. The dual port RAM provides 8 additional addresses for semaphores; to allow either processor to claim privilege over the other processor for functions defined by the software designer. Each side has an interrupt output that can be used to indicate that and data is available this is done by one port writing to address 1FFEh this sets the interrupt output on the other port. The interrupt output is then released when the receiving port reads address 1FFEh. The two bus switches are used to protect the dual port ram so the module may be hot swap safely. Until the module has been fully powered up the MODULE_READY# signal hold the bus switch off. This prevents any signals being shorted to ground while the module is switched off. When the MODULE_READY# signal goes low the all the switches turn on and the signals can pass as normal.

5.15 Ultra I/O The Ultra I/O chip (U10) is use to expand the SC400 features by adding two UARTS, a harddisk controller, additional I/O ports, mouse and keyboard interfaces. It also contains a floppy disk drive controller, a Real Time clock, a parallel port, and an intelligent automatic power management controller and is also ISA plug and play standard (V1.0a) compatible register set.

Main PCB Circuit Description

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The Ultra I/O chip (U10) is connected to the 5Vsupply rail and is therefore connected to the 5Vsystem bus. All I/O addresses are qualified with AEN, as there is no other address on this bus that should conflict with this device so this has been pulled low permanently. The SC400 communicates with the Ultra I/O chip through a series of read write registers. These registers are accessed through programmed I/O. (DMA transfers with this device are not possible with the current circuit arrangement.) The registers are all 8bit, with exception of the IDE data register at port 1F0h, which is 16bit. The port addresses of these registers are shown in the table below. The Ultra I/O chip (U10) is clocked at 14.31818MHz by a crystal (XM1 or XM3) which is controlled from the SC400 via the 14MHz_OFF# signal. It outputs this clock signal via its CLKO1-14 pin and is then potentially divided to give a 3.3V clock source for the Graphics Controller.

5.16 Parallel Port The Ultra I/O has a parallel printer port this has been used by the PMA for additional I/O lines. These functions are listed in the table 8 along with their alternative functions.

Ultra I/O Parallel port usage Pin No.

Signal Name

Description

Alternative Function

138

AUDIO_MODE

Audio Amp Control line

Parallel Port Data-bit 0

137

AUDIO_MUTE

Audio Amp Control line

Parallel Port Data-bit 1

136

AUDIO_SHUTDOWN

Audio Amp Control line

Parallel Port Data-bit 2

135

VPP_ENABLE PCMCIA

Vpp-enable

Parallel Port Data-bit 3

134

SMRESET

Smart card reset

Parallel Port Data-bit 4

133

SMCS1

Smart-Card Chip Select

Parallel Port Data-bit 5

132

SMCS2

Smart-card Chip Select

Parallel Port Data-bit 6

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Main PCB Circuit Description

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Pin No.

Signal Name

Description

Alternative Function

131

SMCS3

Smart-card Chip Select

Parallel Port Data-bit 7

129

SMWP

Smart card write protect

Printer Acknowledge

128

SMDETECT

Smart card detect

Printer Busy

127

UNUSED

N/A

Printer Paper End

126

UNUSED

N/A

Printer Select

144

UNUSED

N/A

Printer Strobe

143

SRESET#

AVR Programming

Printer Auto Line Feed

142

MISO

AVR Programming

Printer Error

141

MOSI

AVR Programming

Printer initialise

140

SCK

AVR Programming

Printer Selected

5.17 Serial Ports The Ultra I/O chip has two 16550A compatible UART's. The base address of which can be set during configuration mode. The PMA sets these addresses to 2F8h and 3E8h for the PCB's COM2 and COM3 respectively, in software

5.18 32KHz Oscillator The 32Khz oscillator is used for triggering the watchdog circuit. During the initial boot up the IPL/BIOS does not trigger the watchdog. With the additional circuitry described below, this clock triggers the watchdog. A link (LK10) is used to select between constant triggering of the watchdog (Pads 2 and 3 soldered together for development purposes) or switched out after 30secs (pads 1 and 2 soldered together normal position). There is also a link (LK11) present to allow this clock to be connected to the display controller. This enable self refresh of the display DRAM during standby mode of the display controller. With out this the display controller cannot refresh DRAMS during standby mode.

5.19 RESET and Watch Dog Circuit The Reset circuit is controlled by the MAX706 (U25). This monitors the 3.3V supply rail and keeps reset asserted when it falls below 3.08V. It releases the reset after 200ms after the supply rises above this threshold. The IC also has a built in watchdog that needs to be toggled before an internal timer reaches 1.6secs. The watchdog output is pulled low when this timeout period is reached but it does not cause a reset, therefore the watchdog output is shorted to the manual reset input (MR). The 555 timer is used in mono-stable mode in order to inhibit the watchdog for 30secs during boot up. This is to allow time for QNX to run the application, which will then trigger the watchdog accordingly. The NAND logic (U37) is used to divert either the 32Khz clock or the SC400 watchdog trigger output to the Watchdog input on the MAX706 according to the state of the 555 Timer output.

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