28 www.xilinx.com FMC XM105 Debug Card User Guide
UG537 (v1.2) September 24, 2010
Chapter 1: XM105
15. 2-Kb EEPROM
A ST Microelectronics M24C02 2-Kb serial IIC bus EEPROM component provides a small 
amount of non-volatile memory storage on the XM105. 
The IIC address of this component is controlled by a combination of the specific board 
interface and chip enable connections to the component inputs on the XM105. Signals GA0 
and GA1 from the board are connected to the chip enable inputs of the M24C02 component 
enables E0 and E1. As shown in Table 1-16, Xilinx boards provide GA0 and GA1 signal 
strapping to 3.3V and GND signals, which creates a different E0 and E1 chip enable decode 
on the E1 and E0 inputs of the EEPROM.   
The IIC memory addressing protocol requires a bus master to initiate communication to a 
peripheral device using a start condition followed by a device select code. The device select 
code consists of a 4-bit Device Type Identifier and a 3-bit Chip Enable Address (E2, E1, E0). 
Bit 0 is used to indicate read/write. The Device Type Identifier for the EEPROM is 1010 
binary. Table 1-17 shows the generic EEPROM Device Select Code as well as specific 
Device Code Select addresses for the EEPROM when the XM105 is connected to boards 
defined in Table 1-1, page 8. 
Table 1-16: M24C02 Enable Input Connections
M24C02 Chip 
Enable Input
FMC HPC 
Control 
Signal 
Connection
SP601 LPC 
Connector
SP605 LPC 
Connector
ML605 LPC 
Connector
ML605 HPC 
Connector
E0 GA1 GND GND 3.3V GND
E1 GA0 3.3V 3.3V GND GND
E2  GND GND GND GND GND
Table 1-17: EEPROM IIC Device Select Code
Bit 7:4
Device Type 
Identifier 
Bit 3 Bit 2 Bit 1  Bit 0 (LSB) Description
1010 E2 E1 E0 Read/Write
M24C02 Device Select Code
1010 0GA0GA1 Read/Write
Connected to XM105
1010 010 Read/Write
Connected to SP601 LPC interface
1010 010 Read/Write
Connected to SP605 LPC interface
1010 001 Read/Write
Connected to ML605 LPC interface
1010 000 Read/Write
Connected to ML605 HPC interface
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