Calibre UCA93 User manual

Calibre UK Ltd 2003

CALIBRE
UCA93 I2C Communications Adapter
Issue 1.0
01/07/2003

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Welcome to the Calibre UCA93 adjustable voltage I2C Adapter. This Adapter provides full I2C
bi-directional compatibility as either a master or slave from within a Windows 98 2000 or
Windows XP environment.
If you have any queries relating to this or any other I2C product supplied by Calibre please visit
our web site www.calibreuk.com.
For technical support please e-mail [e-mail] or send your queries by fax to
(44) 1274 730960, for the attention of our I2C Technical Support Department.
COPYRIGHT
This document and the software described within it are copyrighted with all rights reserved. Under
copyright laws, neither the documentation nor the software may be copied, photocopied, reproduced,
translated, or reduced to electronic medium or machine readable form, in whole or in part, without
prior written consent of Calibre UK Ltd ("Calibre"). Failure to comply with this condition may result in
prosecution.
Calibre does not warrant that this software package will function properly in every
hardware/software environment. For example, the software may not work in combination with
modified versions of the operating system or with certain network Adapter drivers.
Although Calibre has tested the software and reviewed the documentation, CALIBRE MAKES
NO WARRANTY OR REPRESENTATION, EITHER EXPRESS OR IMPLIED, WITH RESPECT TO
THIS SOFTWARE OR DOCUMENTATION, THEIR QUALITY, PERFORMANCE,
MERCHANTABILITY, OR FITNESS FOR A PARTICULAR PURPOSE. THIS SOFTWARE AND
DOCUMENTATION ARE LICENSED 'AS IS', AND YOU, THE LICENSEE, BY MAKING USE
THEREOF, ARE ASSUMING THE ENTIRE RISK AS TO THEIR QUALITY AND PERFORMANCE.
IN NO EVENT WILL CALIBRE BE LIABLE FOR DIRECT, INDIRECT, SPECIAL,
INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO
USE THE SOFTWARE OR DOCUMENTATION, even if advised of the possibility of such damages.
In particular, and without prejudice to the generality of the foregoing, Calibre has no liability for any
programs or data stored or used with Calibre software, including costs of recovering such programs or
data.
Copyright Calibre UK Ltd
(c) 2003 Cornwall House, Cornwall Terrace
Bradford, BD8 7JS. UK.
E-mail: [e-mail]
Web site www.calibreuk.com
All World-wide Rights Reserved
Issue 1.0 01/07/2003
All trade marks acknowledged
Calibre operates a policy of continued product improvement, therefore specifications are subject to
change without notice as products are updated or revised.
E&OE.

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Contents
INTRODUCTION 1
1.1. General Introduction 1
1.2. Packing List 1
1.3. Configuring the Adapter 1
1.4. Bus Termination and Protection 1
1.5. Connecting the Adapter to your System 1
1.6. Bus Capacitance Limitations/Cable Choice 2
1.7. Variable Voltage Bus Power Supply 2
INSTALLING THE ADAPTER UNDER WINDOWS 3
2.1. Introduction 3
2.2. Installing the Adapter 3
LIBRARIES FOR PROGRAMMING IN MICROSOFT WINDOWS ENVIRONMENTS 4
3.1. Introduction 4
3.2. Function Prototypes 5
3.3. Function Description 7
3.3.1. Setup 7
3.3.2. SendAddress 7
3.3.3. WriteByte 8
3.3.4. ReadByte 8
3.3.5. SendStop 8
3.3.6. Restart 8
3.3.7. GetStatus 9
3.3.8. Recover 9
3.3.9. SlaveLastByte 9
3.3.10. BlockWrite 10
3.3.11. SetBlockData 10
3.3.12. BlockWriteStatus 10
3.3.13. BlockRead 10
3.3.14. GetBlockData 11
3.3.15. BlockReadStatus 11
3.3.16. BlockSlaveTransmittter 11
3.3.17. BlockSlaveTransmitterStatus 12
3.3.18. BlockSlaveReceiver 12
3.3.19. BlockSlaveReceiverStatus 13
3.3.20. CheckBusVoltage 13
3.3.21. CheckPullupVoltage 13
3.3.22. Write_IO_Pin 14
3.3.23. Read_IO_Pin 14
3.3.24. SendAddressNoStatus 15
3.3.25. WriteByteNoStatus 15
3.3.26. ReadByteNoStatus 15
3.3.27. SendStopNoStatus 15
3.3.28. RestartNoStatus 16
The Real-Time Bus Monitor 17
Appendix A I2C Communications Adapter Status Codes 18
Appendix B Migration Notes for Existing Calibre I2C Customers 19
When the THE MOST COMMONLY ASKED I2C QUESTIONS 22
General Questions 22
Windows Questions 22

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INTRODUCTION
1.1. General Introduction
The UCA93 is a USB V1.1 to I2C Adapter based on the PIC 16F874 microcontroller using a Philips
PCF8584 for the bus monitor function. It features full I2C bi-directional compatibility as either a master or
slave. I2C connections are made via a 9 way “D” socket. This product complies with the requirements of
EEC Directive 89/336 for EMC and is CE marked.
The UCA93 provides full software control of the I2C bus voltage, bus speed and pull up resistors. Two
spare IO pins are available to the user.
The software functions supplied with the Adapter have been designed to feel as familiar as possible to
customers with existing Calibre AT or PCI bus I2C adapters. Nevertheless there are some unavoidable
differences between the way the UCA93 works and previous generations of products. Customers are
strongly recommended to read Appendix B which deals with migration issues.
New software block functions have been added to take advantage of the USB port’s high data rate.
1.2. Packing List
Your I2C Communications Adapter is supplied with the following items:-
A. I2C CD ROM
B. The UCA93 Adapter and USB cable
1.3. Configuring the Adapter
NOTE
There are no user adjustable components within the Adapter. The Adapter contains static
sensitive devices.
Read the following section to change the configuration.
1.4. Bus Termination and Protection
Normally the system to which the I2C Communications Adapter is to be connected should already have
master pull up resistors fitted to the SCL and SDA lines. If this is not the case, pull up resistors to the
+V(adjustable) can be configured as part of the software set up.
1.5. Connecting the Adapter to your System
The USB cable MUST be connected between the PC and the Adapter.
All I2C connections are made via a 9 way “D” socket:
Pin Function
10V
20V
30V
40V
5NC
6 SDA (Bi-directional)
7 +V (variable voltage)
8 SCL (Bi-directional)
9NC
The Adapter also provides two digital input / output pins, which are connected via a 0.1” 4 way PCB
connector.
IO 0 is an open drain output which requires an external pull up and can be used on systems which are
not 5V tolerant. If IO 0 is used as an input it MUST be connected to a 5V system.

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IO 1 is a 5V TTL input and can only be used on 5V tolerant systems.
Pin Function
1 NC – DO NOT CONNECT
2IO0
3IO1
40V
1.6. Bus Capacitance Limitations/Cable Choice
The maximum allowable capacitance on the I2C bus in normal mode depends on the value of the SCL
and SDA master pull-ups, but never exceeds 400pF. Refer to Phillips Technical Handbook Book 4 Parts
12a and 12b for further details. Care should be taken in choosing a length and type of interconnecting
cable, which will not exceed this limit.
For most systems with a distance of a few metres between the I2C Communications Adapter and the
target system, screened cable is NOT recommended, as it is likely to introduce too much capacitance.
However, the EMC performance of an unscreened cable is always potentially poorer than a screened
one. The Adapter's EMC performance even with an unscreened cable is good - but this may not be true
of the target system! If you are in any doubt at to the best way to connect up your system with EMC in
mind please contact your supplier or Calibre for advice.
1.7. Variable Voltage Bus Power Supply
Pin 7 on the “D” connector is connected to the variable bus voltage power rail. Power for external
circuitry can be drawn from here, but care should be taken never to short it to 0V or to exceed 250mA
loading. It is short circuit and overload protected by a self-resetting thermal fuse but prolonged shorting
could cause the UCA93 to generate an excessive amount of heat.
The bus voltage is set via software, in the range 2V to 5V.
NOTE that if a bus voltage greater 4.2V is selected the output will be 5V.

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INSTALLING THE ADAPTER UNDER WINDOWS
2.1. Introduction
This section details the installation of the UCA93 I2C communications Adapter under Windows 98® /
Windows2000® and Windows XP®.
The appearance of the dialog boxes during the installation of new hardware varies depending on the
version of Windows.
The Adapter supports plug and play via the USB port.
2.2. Installing the Adapter
Connect the Adapter to the PC using the USB cable, the power light will illuminate.
The operating system will detect the installation of new hardware, follow the set up wizard instructions.
Either browse the CD or select the “have disc” option select the FTD2XX.inf.
The wizard will then install the device drivers.
IMPORTANT NOTE
Windows XP includes a driver for the USB interface device used in the Adapter, and will normally install
this. The driver installed from the XP disc WILL NOT WORK with this Adapter.
If you are using Windows XP you can check that the correct driver is installed by
1) Right click on the “My Computer Icon”
2) Select properties
3) Select the Hardware Tab and click “Device Manager”
4) Expand the “Universal Serial Bus Controllers”
5) If the driver is provided by Microsoft you need to select the update driver then browse
for and select the FTD2XX.inf
6) Once installed correctly the FTDI FT8U2XX Device should be listed
PLEASE NOTE The FTD2XX.inf is NOT digitally signed but is correct.

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LIBRARIES FOR PROGRAMMING IN MICROSOFT WINDOWS ENVIRONMENTS
3.1. Introduction
Each utility is documented in a standard format which lists its name, usage, function and effect on the
Adapter is given. The Adapter should be setup prior to any data transfer.
Within the DLL there are two versions of some functions e.g. SendAddress and SendAddressNoStatus,
the first provides legacy support for software written for other Calibre UK Ltd I2C products, the second
format does not return the status.
3.1.1. Legacy Function
The following changes have had to be made to the legacy functions
1) The parameters passed to the setup function are specific to the Adapter
2) The status wait has been removed and is now controlled by hardware, the Adapter will wait up
to 500 micro seconds before returning an error code indicating that the transfer failed.
3) The Setnack is now changed on the read you require the acknowledge state to change NOT on
the byte before.
4) There is no longer a need to perform a Trash read after a restart.
3.1.2. No Status Functions
The xxNoStatus functions provide faster transfers as they do not require the USB bus to change
direction between writing and reading. The function prototypes are included in the manual but care
MUST be taken when using these functions not to corrupt the I2C with uncontrolled transfers. These
functions are ONLY to be used when users are 100% certain that all devices on the I2C WILL
acknowledge their address and that there is a single master.
PLEASE NOTE NO TECHNICAL SUPPORT IS AVAILABLE FOR THESE FUNCTIONS
Calibre UK recommend using the block functions detailed below
3.1.3. Block Functions
To aid users wishing to transfer data without the complication of having to write a I2C transfer protocol a
number of Block functions have been added. DO NOT exceed the data transfer limitations described in
the individual functions as this will cause errors and data corruption.
C and C++ users will undoubtedly wonder why they are passing data to the DLL when they could much
more efficiently pass a pointer, unfortunately not all the development environments this Adapter will be
used on support pointers.

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3.2. Function Prototypes
If you are using ‘C’ or ‘C++’ copy the file CALUCA.H into the directory containing your project and add
the line:
#include " CALUCA.H"
The following functions are implemented in the windows libraries:-
extern __declspec(dllimport) int WINAPI Setup (int, int, int, int, int);
extern __declspec(dllimport) int WINAPI SendAddress (int, int);
extern __declspec(dllimport) int WINAPI WriteByte(int);
extern __declspec(dllimport) int WINAPI ReadByte(int);
extern __declspec(dllimport) int WINAPI SendStop(void);
extern __declspec(dllimport) int WINAPI Restart (int, int);
extern __declspec(dllimport) int WINAPI GetStatus(void);
extern __declspec(dllimport) int WINAPI recover(void);
extern __declspec(dllimport) void WINAPI SlaveLastByte(void);
extern __declspec(dllimport) int WINAPI DLLVersion(void);
extern __declspec(dllimport) void WINAPI SendAddressNoStatus(int , int, int);
extern __declspec(dllimport) void WINAPI RestartNoStatus(int , int, int );
extern __declspec(dllimport) void WINAPI WriteByteNoStatus(int );
extern __declspec(dllimport) void WINAPI ReadByteNoStatus(int );
extern __declspec(dllimport) void WINAPI SendStopNoStatus(void);
extern __declspec(dllimport) int WINAPI SetBlockData(int);
extern __declspec(dllimport) int WINAPI BlockWriteStatus (void);
extern __declspec(dllimport) int WINAPI BlockWrite(int , int , int ,int, int );
extern __declspec(dllimport) int WINAPI GetBlockData(void);
extern __declspec(dllimport) int WINAPI BlockReadStatus(void);
extern __declspec(dllimport) int WINAPI BlockRead(int , int , int , int, int );
extern __declspec(dllimport) int WINAPI BlockSlaveTransmitterStatus(void);
extern __declspec(dllimport) int WINAPI BlockSlaveTransmitter( int );
extern __declspec(dllimport) int WINAPI BlockSlaveReceiverStatus(void);
extern __declspec(dllimport) int WINAPI BlockSlaveReceiver(int , int );
extern __declspec(dllimport) int WINAPI Write_IO_Pin (int , int );
extern __declspec(dllimport) int WINAPI Read_IO_Pin (int );
extern __declspec(dllimport) int WINAPI CheckBusVoltage(void);
extern __declspec(dllimport) int WINAPI CheckPullupVoltage(void);

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If you are using Visual Basic copy the file UCA93LV.BAS into the directory containing your project and
add the file UCA93LV.BAS to your project:
The following functions are implemented in the windows libraries:-
Public Declare Function Setup% Lib "USBDLL_XP.dll" (ByVal OwnAddress%, ByVal Sclk%, ByVal
BusVoltage%, ByVal PullUpsOn%, ByVal SlaveBlockTimeout%)
Public Declare Function SendAddress% Lib "USBDLL_XP.dll" (ByVal SlaveAddress%, ByVal setnack%)
Public Declare Function Restart% Lib "USBDLL_XP.dll" (ByVal SlaveAddress%, ByVal setnack%)
Public Declare Function WriteByte% Lib "USBDLL_XP" (ByVal wrdata%)
Public Declare Function ReadByte% Lib "USBDLL_XP.dll" (ByVal setnack%)
Public Declare Function SendStop% Lib "USBDLL_XP.dll" ()
Public Declare Function GetStatus% Lib "USBDLL_XP.dll" ()
Public Declare Function Recover% Lib "USBDLL_XP.dll" ()
Public Declare Function SlaveLastByte% Lib "USBDLL_XP.dll" ()
Public Declare Function DLLVersion% Lib "USBDLL_XP.dll" ()
Public Declare Function SetBlockData% Lib "USBDLL_XP.dll" (ByVal DataVal%)
Public Declare Function GetBlockData% Lib "USBDLL_XP.dll" ()
Public Declare Function BlockSlaveTransmitter% Lib "USBDLL_XP.dll" (ByVal TimeOut%)
Public Declare Function BlockSlaveTransmitterStatus% Lib "USBDLL_XP.dll" ()
Public Declare Function BlockSlaveReceiver% Lib "USBDLL_XP.dll" (ByVal NoBytesToTransmit%,
ByVal TimeOut%)
Public Declare Function BlockSlaveReceiverStatus% Lib "USBDLL_XP.dll" ()
NOTE A type is defined in UCA93LV.BAS to help passing parameters to the DLL, if you do not
wish to use this local variables MUST be declared as static

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3.3. Function Description
3.3.1. Setup
Function specification int Setup(int OwnAddress, int ClockSpeed, int BusVoltage, int PullUpsOn, int
SlaveBlockTimeout)
Parameters are: int ownaddress
This is the I2C address to which the Adapter is to respond in slave mode. This
forms the upper 7 bits of the 8 bit address, the lowest bit being the read(1) or
write(0) bit. This means that if ownaddress = 57H the card will respond to a
write address of AEH and a read address of AFH.
int ClockSpeed
This is the clock rate (bit rate for the I2C serial bus) when operating as a
master. For 400kHz enter 400, for 90kHz enter 90.
Maximum value 400 minimum value 25
int BusVoltage
The desired bus voltage multiplied by 100 e.g. 330 would give a bus voltage
3.3V. Please note that if a value between 4.2V and 5V is requested the output
will be 5V.
Maximum value 500 (5V) Minimum value 180 (1.8V).
int PullUpsOn
Set (1) to turn the pull up resistors on, clear (0) to turn them off.
int SlaveBlockTimeout
This parameter is only used by the slave block functions. If the Master has not
completed the transfer in this period (seconds) the Adapter will abort the
transfer and return an error code.
Range 1 – 255 seconds. NOTE: setting this value to 0 will prevent the Adapter
from timing out the slave block function.
Parameters returned If the software fails to find the driver error code 8000H is returned otherwise the
status is returned.
Prerequisites None.
Functional description This function initialises Adapter ready for I2C transfers.
3.3.2. SendAddress
Function specification Int SendAddress(int SlaveAddress, int SetNack)
Parameters are: int SlaveAddress
This is the address to be accessed via the I2C, e.g. A0H.
int SetNack
This controls whether the Adapter transmits an acknowledge down the I2C bus
on reception of a byte. The last byte received during a transfer must not be
acknowledged, in all other cases acknowledge must be enabled. If SetNack = 0
then acknowledge is enabled, if SetNack = 1 then acknowledge is disabled.
Normally there will be another transfer (data read or write) after the
SendAddress and so SetNack is enabled (0);
Parameters returned int ErrCode.
If the transfer time out occurs error code 8001H is returned otherwise the
status is returned.
Prerequisites The Adapter must be configured by running Setup.
Functional description The function waits for the bus to be free then sends the slave address.
The function waits for the address to be sent. Should a time-out occur during
the sending of an address then an error code 8001H is returned, otherwise the
status is returned.

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WriteByte
Function specification Int WriteByte(int DataByte)
Parameters are: int DataByte
This is the byte of data to be written.
Parameters returned int ErrCode.
If the transfer time out occurs error code 8002H is returned otherwise the
status is returned.
Prerequisites Adapter must be configured using Setup, start and write address sent by
SendAddress.
Functional description The function writes the data to the Adapter and then waits for it to be sent.
Should a time-out occur during the sending of the data then error code 8002H
is returned, otherwise the status is returned.
WriteByte is compatible with both master write and slave write modes.
3.3.3. ReadByte
Function specification Int ReadByte(int SetNack)
Parameters are: int SetNack
This controls whether the Adapter transmits an acknowledge down the I2C bus
on reception of a byte. The last byte received during a transfer must not be
acknowledged, in all other cases acknowledge must be enabled. If SetNack = 0
then acknowledge is enabled, if SetNack = 1 then acknowledge is disabled.
Parameters returned int I2CData
If a time-out occurs the ErrCode 8003H is returned, otherwise the data is
returned.
Prerequisites Adapter must be configured using Setup, start and read address sent by
SendAddress.
Functional description The data is read from the Adapter.
ReadByte is compatible with both master read and slave read modes.
3.3.4. SendStop
Function specification Int SendStop(void)
Parameters are: None
Parameters returned int ErrCode.
If the transfer time out occurs error code 8006H is returned otherwise the
status is returned.
Prerequisites Adapter must be configured using Setup. Should normally only be used at the
end of a transmission. Correct acknowledge sequence must have been applied
if the transmission was a read.
Functional description Instructs the Adapter to send a stop code and wait for it to be sent.
Should a time-out occur during the sending of a stop then an error code 8006H
is returned, otherwise the status is returned.
3.3.5. Restart
Function specification Int Restart(int SlaveAddress, int SetNack)
Parameters are: int slaveaddress
The address to be accessed via the I2C, e.g. A1H.
int SetNack
This controls whether the Adapter transmits an acknowledge down the I2C bus
on reception of a byte. The last byte received during a transfer must not be
acknowledged, in all other cases acknowledge must be enabled. If SetNack = 0
then acknowledge is enabled, if SetNack = 1 then acknowledge is disabled. It is
normal to read data after a restart and hence SetNack will normally be 0.
Parameters returned int ErrCode
If the transfer time out occurs error code 8004H is returned otherwise the
status is returned.
Prerequisites Adapter must be configured using Setup. A start and slave address must have
previously been sent using SendAddress.

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Usually a data pointer would already have been written using WriteByte.
Functional description Sends a start code and the slave address.
The function waits for the address to be sent. Should a time-out occur during
the sending of an address then an error code 8004H is returned, otherwise the
status is returned.
3.3.6. GetStatus
Function specification:Int GetStatus(void)
Parameters are: None
Parameters returned int I2Cstatus
The current value of the bus status is returned.
Prerequisites Adapter must be configured using Setup.
Functional description The function reads status word from the Adapter and returns it.
3.3.7. Recover
Function specification Int Recover(void)
Parameters are: None
Parameters returned int ErrCode.
If the bus recovery failed error code 800FH is returned otherwise the status is
returned.
Prerequisites Adapter must be configured using Setup.
Functional description This function clears all USB buffers and issues three consecutive stop
commands on the bus, with a delay of about 5uS in between. It then clears the
Adapter registers and reads the status. This should normally set the Adapter
into a known idle state when a bus error or other problem has occurred.
If the status does not indicate bus free or the Bus Error bit is still set then
800FH is returned otherwise the status is returned.
3.3.8. SlaveLastByte
Function specification void SlaveLastByte(void)
Parameters are: None
Parameters returned None.
Prerequisites Adapter must be configured using setup. This function would normally only be
called following the end of a transmission in slave write mode - when the
Adapter is being read as a slave, by another master, not when writing to a slave
using the Adapter.
Functional description This function is used when the Adapter is a slave being read by a master
elsewhere on the bus - the Adapter is in slave write mode. The function must
be called immediately after the master indicates the last byte has been read (by
not acknowledging that byte). This function is required to clear the I2C data
lines so that the master can send a stop signal.

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3.3.9. BlockWrite
Function specification void BlockWrite(int SlaveWriteAddress, int MSB_WordAddress, int
LSB_WordAddress,int NoBytesToSend, int NoTries )
Parameters are: int SlaveAddress
This is the address to be accessed via the I2C, e.g. A0H
int MSB_WordAddress, int LSB_WordAddress
This is the location within the slave for the data. The use of two bytes allows
users to communicate with devices requiring two byte pointers e.g. 24C64
EEPROMS. If one (or both) of the word addresses are not required set the
value to a number greater than 255 and it will not be transmitted.
int NoBytesToSend
The number of bytes to be sent which MUST be pre loaded into the driver
buffers. The maximum size of this buffer is 2048 exceeding this WILL cause
the data to be corrupted.
Int NoTries
This is the number of times the Adapter is to try to send the address.
Parameters returned None.
Prerequisites Adapter must be configured using Setup. The data MUST be loaded into the
driver buffers PRIOR to calling this functions (see SetBlockData).
Functional description This function causes the Adapter to send a block of data via the I2C bus.
3.3.10. SetBlockData
Function specification int SetBlockData(int DataVal)
Parameters are: Int DataVal
Parameters returned Returns an unused integer.
Prerequisites Adapter must be configured using setup.
Functional description This stores data in the driver buffers read to be sent by the BlockWrite function.
MAXIMUM DATA SIZE 2048 bytes.
3.3.11. BlockWriteStatus
Function specification int BlockWriteStatus (void))
Parameters are: None
Parameters returned int TransferStatus.
Returns 0 if the transfer has not been completed.
Returns the I2C Bus status if the transfer is completed.
Returns 9009H if the transfer time out.
Prerequisites Adapter must be configured using Setup. Data must have been sent using the
BlockWrite function.
Functional description Returns the current status of the BlockWrite transfer NOTE this function will
time out if the block is not sent in NoBytes / 100 seconds (or 1 second which
ever is the greater).
3.3.12. BlockRead
Function specification void BlockRead(int SlaveAddress, int MSB_WordAddress, int
LSB_WordAddress, int NoBytesToRead, int NoTries )
Parameters are: int SlaveAddress
This is the address to be accessed via the I2C, e.g. A0H If the SlaveAddress is
is a read address then the Word Addresses WILL NOT be sent.
int MSB_WordAddress, int LSB_WordAddress
This is the location within the slave for the data. The use of two bytes allows
users to communicate with devices requiring two byte pointers e.g. 24C64
EEPROMS. If one (or both) of the word addresses are not required set the
value to a number greater than 255 and it will not be transmitted.
int NoBytesToRead
The number of bytes to be sent which MUST be pre loaded into the driver
buffers. The maximum size of this buffer is 2048 exceeding this WILL cause
the data to be corrupted.
Int NoTries

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This is the number of times the Adapter is to try to send the address.
Parameters returned None.
Prerequisites Adapter must be configured using setup.
Functional description This function causes the Adapter to read a block of data via the I2C bus.
3.3.13. GetBlockData
Function specification int GetBlockData(void)
Parameters are: None
Parameters returned int RdData.
Prerequisites Adapter must be configured using Setup. The block read function MUST have
been called and the BlockReadStatus should be called to determine if the
transfer has been completed
Functional description Read data from the driver buffers. MAXIMUM DATA SIZE 2048 bytes.
3.3.14. BlockReadStatus
Function specification int BlockReadStatus (void))
Parameters are: None
Parameters returned int TransferStatus.
Returns 0 if the transfer has not been completed.
Returns the I2C Bus status if the transfer is completed.
Returns 900AH if the transfer time out.
Prerequisites Adapter must be configured using Setup. The transfer must be started using
the BlockRead function.
Functional description Returns the current status of the BlockWrite transfer NOTE this function will
time out if the block is not sent in NoBytes / 100 seconds (or 1 second which
ever is the greater).
3.3.15. BlockSlaveTransmittter
Function specification int BlockSlaveTransmitter(int NoBytesToTransmit, int Timeout)
Parameters are: int NoBytesToTransmit
The number of bytes to be sent which MUST be pre loaded into the driver
buffers. The maximum size of this buffer is 2048 exceeding this WILL cause
the data to be corrupted.
Int Timeout
If the transfer is not completed within Timeout seconds the
BlockSlaveTansmitStatus will return a Timeout error.
Parameters returned Returns an unused integer.
Prerequisites Adapter must be configured using Setup. The data MUST be loaded into the
driver buffers PRIOR to calling this functions (see SetBlockData).
Functional description This function causes the Adapter to respond to I2C master requests for data.
This function supports transfers where the master sends WordAddress pointers
to data locations within the transfer block. If the master does not request to
read data from the beginning of the data block the Adapter will remove the data
from the buffer until the byte requested by the master is reached it will then
transmit the data.
Should the master exceed the number of bytes available the Adapter will
honour all requests for data and the overflow will be reported see
BlockSlaveTransmitterStatus.
This function allows the user to emulate simple slave devices e.g. EEPROM
BUT once the master has completed the transfer the Adapter will NOT respond
to any further requests for data until the BlockSlaveTransmitter is called again.

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3.3.16. BlockSlaveTransmitterStatus
Function specification int BlockSlaveTransmitterStatus (void))
Parameters are: None
Parameters returned int TransferStatus.
Returns 0 if the transfer has not been completed.
Returns the a status if the transfer is completed (see below).
Bit 0 Set if a write address received
Bit 1 Set if word address 0 received
Bit 2 Set if word address 1 received
Bit 3 Set if restart received
Bit 4 Stop detected
Bit 5 Set if the transfer timeout (Value in Setup function) occurred
Returns 900BH if the transfer time out.
Prerequisites Adapter must be configured using Setup. The transfer must be started using
the BlockSlaveTransmittter function.
Functional description Returns the current status of the BlockSlaveTransmittter transfer NOTE this
function will time out the BlockSlaveTransmittter function.
Read two bytes of data from the Adapter using GetBlockData to determine
where the master read from in the block (high byte first), read the next two
bytes to determine how many bytes of data the master read from the slave
(high byte first), read 1 byte to determine the status.
3.3.17. BlockSlaveReceiver
Function specification int BlockSlaveReceiver (int NoBytesToReceive, int Timeout)
Parameters are: int NoBytesToReceive
The number of bytes to expected from the master. NOTE if the protocol
requires the master to transmit one or more word address bytes these MUST
be included in the NoBytesToReceive. The maximum size of this buffer is 2048
exceeding this WILL cause the data to be corrupted.
PLEASE NOTE THIS MUST INCLUDE THE NUMBER OF WORD ADDRESS
BYTES IF THEY ARE TRANSMITTED BY THE MASTER
Int Timeout
If the transfer is not completed within Timeout seconds the
BlockSlaveReceiverStatus will return a Timeout error.
Parameters returned Returns an unused integer.
Prerequisites Adapter must be configured using Setup.
Functional description This function causes the Adapter to respond to I2C master transmission of
data. This function supports transfers where the master sends WordAddress
pointers to data locations within the transfer block.
Should the master exceed the number of bytes expected the Adapter will
honour all transfers for data and the overflow will be reported see
BlockSlaveReceiverStatus.
This function allows the user to emulate simple slave devices e.g. EEPROM
BUT once the master has completed the transfer the Adapter will NOT respond
to any further requests for data until the BlockSlaveReceiver is called again.

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3.3.18. BlockSlaveReceiverStatus
Function specification int BlockSlaveReceiverStatus (void))
Parameters are: None
Parameters returned int TransferStatus.
Returns 0 if the no data has been received.
Returns the a status if the transfer is completed (see below).
Bit 0 Not Used
Bit 1 Not Used
Bit 2 Not Used
Bit 3 Not Used
Bit 4 Stop detected
Bit 5 Set if the transfer timeout (Value in Setup function) occurred
Returns 900DH if the expected number of bytes is exceeded
Returns 900CH if the transfer time out.
Prerequisites Adapter must be configured using Setup. The transfer must be started using
the BlockSlaveReceiver function.
Functional description Returns the current status of the BlockSlaveReceiver transfer NOTE this
function will time out the BlockSlaveReceiver function.
Read two bytes of data from the Adapter using GetBlockData to determine how
many bytes of data the master read from the slave.
Read the first two bytes to determine how many bytes of data the master read
from the slave (high byte first), read 1 byte to determine the status.
3.3.19. CheckBusVoltage
Function specification int CheckBusVoltage (void))
Parameters are: None
Parameters returned int BusVoltage
Returns the I2C bus output voltage multiplied by 100.
Returns 0x800C if the transfer timed out.
Prerequisites Adapter should be configured using Setup. If this is not done the I2C bus
voltage will default to 3.3V.
Functional description Returns the current bus voltage multiplied by 100 as measured on pin 7 of the
output socket. For example, will return 330 for a 3.3V bus voltage , 500 for a
5.0V bus voltage and 200 for a 2.0V bus voltage.
3.3.20. CheckPullupVoltage
Function specification int CheckPullupVoltage (void))
Parameters are: None
Parameters returned int PullupVoltage
Returns the I2C pullup voltage multiplied by 100 measured upstream of the
output overcurrent protection device.
Returns 0x800C if the transfer timed out.
Prerequisites Adapter should be configured using Setup. If this is not done the I2C bus
voltage will default to 3.3V.
Functional description The pullup voltage is the same as the I2C output voltage but measured
upstream of the resettable polyfuse protection device. Returns the current
pullup voltage multiplied by 100. For example, will return 330 for a 3.3V pullup
voltage , 500 for a 5.0V pullup voltage and 200 for a 2.0V pullup voltage. If the
pullup voltage differs from the bus voltage (measured by the previous function)
by more than a few tens of millivolts then too much current is being drawn from
the Adapter. No more than 250mA should be drawn from the Adapter.

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3.3.21. Write_IO_Pin
Function specification int Write_IO_Pin (int IONumber, int IOState)
Parameters are:int IONumber
The number of the IO pin (0 or 1) to be driven
int IOState
The required state (0 or 1) of the selected IO pin
Parameters returned int
Returns a 0 if function successful.
Returns 0x800D if the transfer timed out.
Prerequisites None
Functional description Two spare IO pins are available to drive external logic. IO0 is on PL1 pin 2 and
is an open drain driver. When driven low it can sink up to 10mA, when high it is
high impedance and cannot source current. A pullup resistor should be fitted to
the desired rail which should not exceed +5V. IO1 is on PL1 pin 3 and is a
complementary driver which can source or sink up to 10mA. Its logic levels are
fixed at 0V and +5V nominal.
3.3.22. Read_IO_Pin
Function specification int Read_IO_Pin (int IONumber)
Parameters are:int IONumber
The number of the IO pin (0 or 1) to be read
Parameters returned int
Returns the state (0 or 1) of the chosen IO pin if function successful.
Returns 0x800D if the transfer timed out.
Prerequisites None
Functional description Two spare IO pins are available which can be driven by external logic. IO0 is
on PL1 pin 2 and IO1 is on PL1 pin 3. These pins are normally high impedance
input unless specifically driven by the Write_IO_Pin function. They can be
driven high or low by external logic then read by the Read_IO_Pin function.
Normal 5V CMOS logic levels (0 < 1.5V, 1 > 3.5V) should be applied for reliable
reading.

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3.3.23. SendAddressNoStatus
Function specification void SendAddressNoStatus(int SlaveAddress, int SetNack, int NoTries)
Parameters are: int SlaveAddress
This is the address to be accessed via the I2C, e.g. A0H.
int SetNack
This controls whether the Adapter transmits an acknowledge down the I2C bus
on reception of a byte. The last byte received during a transfer must not be
acknowledged, in all other cases acknowledge must be enabled. If SetNack = 0
then acknowledge is enabled, if SetNack = 1 then acknowledge is disabled.
Normally there will be another transfer (data read or write) after the
SendAddress and so SetNack should be enabled (0);
Int NoTries
This is the number of times the Adapter is to try to send the address.
Parameters returned None.
Prerequisites The Adapter must be configured by running Setup.
Functional description The function waits for the bus to be free. Then sends the slave address with the
appropriate acknowledge.
The acknowledge must equal 0.
The function will generate a start and send the address. If the slave does not
acknowledge then the Adapter will generate a stop. It will try to send the
address a number of times equal to NoTries.
3.3.24. WriteByteNoStatus
Function specification void WriteByteNoStatus(int DataByte)
Parameters are: int DataByte
This is the byte of data to be written.
Parameters returned None.
Prerequisites Adapter must be configured using Setup, start and write address sent by
SendAddressNoStatus.
Functional description The function writes the data to the Adapter and then waits for it to be sent.
WriteByteNoStatus is compatible with both master write and slave write modes.
3.3.25. ReadByteNoStatus
Function specification Int ReadByte(int SetNack)
Parameters are: int SetNack
This controls whether the Adapter transmits an acknowledge down the I2C bus
on reception of a byte. The last byte received during a transfer must not be
acknowledged, in all other cases acknowledge must be enabled. If SetNack = 0
then acknowledge is enabled, if SetNack = 1 then acknowledge is disabled.
Parameters returned None
Prerequisites Adapter must be configured using Setup, start and read address sent by
SendAddressNoStatus.
Functional description The data is read from the Adapter.
ReadByteNoStatus is compatible with both master read and slave read modes.
3.3.26. SendStopNoStatus
Function specification void SendStopNoStatus(void)
Parameters are: None
Parameters returned None.
Prerequisites Adapter must be configured using Setup. Should normally only be used at the
end of a transmission.
Functional description Instructs the Adapter to send a stop code and wait for it to be sent.

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3.3.27. RestartNoStatus
Function specification void RestartNoStatus(int SlaveAddress, int SetNack, int NoTries)
Parameters are: int SlaveAddress
The address to be accessed via the I2C, e.g. A1H.
int SetNack
This controls whether the Adapter transmits an acknowledge down the I2C bus
on reception of a byte. The last byte received during a transfer must not be
acknowledged, in all other cases acknowledge must be enabled. If SetNack = 0
then acknowledge is enabled, if SetNack = 1 then acknowledge is disabled. It is
normal to read data after a restart and hence SetNack will normally be 0.
Int NoTries
This is the number of times the Adapter is to try to send the address
Parameters returned None
Prerequisites Adapter must be configured using Setup. A start and slave address must have
previously been sent using SendAddressNoStatus.
Usually a data pointer would already have been written using
WriteByteNoStatus.
Functional description Sends a start code and the slave address.

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The Real-Time Bus Monitor
To install the monitor run the setup program located in the \CD_USB\USB_Monitor folder, follow the
instructions given by the installation wizard.
Before attempting to run the monitor program ensure that the device drivers are installed correctly in
accordance with this manual.
The program UI2C_MONITOR.EXE is a windows based non-invasive real-time bus monitor which
records activity on an I2C-bus. The transfers are processed into a simple to read format which can be
saved to the PC hard disc.
The monitor can be configured to capture all transfers or alternatively it can capture all transfers
between a start and end address. These features allow the user to capture only those transfers which
are of interest.
Every effort has been made to ensure that the monitor captures all of the transfers it is possible that the
program may miss part of a transfer on heavily loaded I2C buses, this is due to the operating system
servicing other hardware and / or applications. To minimise the amount of data missed we recommend
that you close as many windows applications as possible especially all windows messaging applications,
e-mail and FindFast. We also recommend that you run the application from a 900MHz PC (or better),
note the application will run on a lesser specification PC but you are likely to miss more data.
The following mnemonics are used by the monitor program.
SaXX Start code followed by address, acknowledged.
SnXX Start code followed by address, not acknowledged.
DaXX Data byte, acknowledged.
DnXX Data byte, not acknowledged.
STOP Stop code.
BUS ERROR A bus error has occurred. This is non-fatal to the monitor but a small amount of data
may have been lost whilst recovery was taking place.