Scenix I2C/UART User manual

© 1999 Scenix Semiconductor, Inc. All rights reserved. - 1 - www.scenix.com
Scenix™ and the Scenix logo are trademarks of Scenix Semiconductor, Inc.
September 1999
I2C/UART Demo Board
Quickstart Guide
1.0 Introduction
This guide is designed to get you started with the Scenix I2C/UART Demo kit.
The following items are included with the I2C/UART demo kit:
• 9V or greater power supply with a current capacity of 300mA or greater.
• 9-pin to 9-pin serial cable.
• I2C/UART demo board
• I2C/UART demo board users manual
• Floppydiskcontainingdemosourcecode,EEPROMdatasheet,I2Cspecification,MAX232datasheetandthedemoboard
circuit diagram
• Quickstart guide
Figure 1-1. I2C/UART Demo Board Layout
RS-232
Connector
POT
Voltage
RS-232
Reset
SX28AC
I/O Jumpers
Regulator
EEPROM
ISP/ISD Header
Transceiver
SX28AC
1
Reset RS-232
Connector
RS-232
Transceiver
2
RS-232
Connector
RS-232
Transceiver
3
ISP/ISD Header
PWR EN Jumpers
PWR EN Jumpers
50 MHz
XTAL
8 MHz
XTAL
50 MHz
XTAL
8 MHz
XTAL
PWR
Power
Supply
Connector
Oscillator
Selection
Jumpers
Selection
Jumpers
LED
Prototype Area

© 1999 Scenix Semiconductor, Inc. All rights reserved. - 2 - www.scenix.com
I2C/UART Demo Board Quickstart Guide
2.0 How to Run the I2C/UART Demo
The I2C/UART demo software utilizes a PC serial connection to give the user access to SX implemented I2C masters,
allowing the user to read and write to an on-board I2C EEPROM device.
2.1 Steps
1. Ensure jumpers JP1 through JP4 are all present as these jumpers give power to the SX devices.
2. Ensure the following jumper settings are selected:
• 8/50:Run SX 1 in 50Mhz mode
• MM: Multi-Master mode selected for SX 2. (Arbitration active)
• MSTR:Run I2C master on SX 2
• SL:Run slave on SX 2
• 8/50: Run SX 2 in 50Mhz mode
3. Check the four jumpers JP13 through P16 are installed for 50MHz operation. (All across pins 1-2).
4. Connect a serial cable between UART 3 and your PC. Load Hyper Terminal or any such terminal program and set the
terminal options as follows:
• 19200 Baud rate.
• 8 Data bits
• No parity checking
•1Stopbit
• No flow control
5. Connect power to the AC adapter connector and check the power LED is “on” indicating the board is powered.
6. Press the reset buttons associated with both SX devices.Your terminal screen should now display the following:
SX I2C/UART Demo2
Multi-Master Mode
Devices Found at: 40 50 A0 A2 A4 A6 A8 AA AC AE
R - Read Saved Sentence
S - Save a Sentence
>
If this is not the case, check steps 1 to 7 again. Check the voltage level of VCC for 5V and adjust potentiometer R15 if
needed.
7. The addresses of slave devices found between A0h to AEh correspond to one of the 8 banks of the EEPROM. Each
bank can store up to 256 characters. Once you see these addresses on your terminal, you can follow the instructions
and read/write strings to the on board EEPROM. You should also notice the addresses 40h and 50h, as these corre-
spond to the SX slave devices. Address 40h corresponds to the SX-2 slave device and 50h corresponds to SX-1. The
two SX slave devices will simulate a read only EEPROM which contains an identification string only. More complexity
can easily be added to the SX slaves.
8. Once you have tested SX-2 is running correctly and you can read your saved messages from the EEPROM, you can
connect the serial cable to UART 1 and do the same but this time from one of the SX-1 masters. Once you have
plugged in the serial cable to UART 1, press reset for SX-1 to display the prompts again. You will now be able to read
the same messages out of the same EEPROM but from the SX running dual masters. You can do the same from
UART 2 to activate the second master running on SX-1 however this second I2C master is not connected to the same
I2C bus and therefore cannot access the EEPROM or SX-2. Testing this master will require to add an EEPROM device
to the prototype area and be connect it to I2C-1 bus.
Note:For SX-1, it is not possible to access its own slave (50h) reliably as this puts too much strain on the ISR, by
executing dual UARTs, dual I2C masters, and an I2C slave.