emc2106 Standard Microsystems Corp., emc2106 Datasheet - Page 23

• Manufacturer Part Number: emc2106
• Description: Emc2106 Dual Rpm-based Linear Fan Controller With Hardware Thermal Shutdown
• Manufacturer: Standard Microsystems Corp.

Dual RPM-Based Linear Fan Controller with Hardware Thermal Shutdown
Datasheet
APPLICATION NOTE: It is recommended that the EEPROM that is used be an AT24C02B or equivalent device.
APPLICATION NOTE: No other SMBus Master should exist on the SMDATA and SMCLK lines. The presence of
SMSC EMC2106
START
0-> 1
ACK
0
ADDRESS
Data (01h)
0101_111
Register
SLAVE
XXh
Note: The shaded columns represent data sent from the EMC2106 to the EEPROM device.
The EEPROM should be loaded to mirror the register set of the EMC2106 with the desired
configuration set. All undefined registers in the EMC2106 register set should be loaded with 00h in the
EEPROM. Likewise, all registers that are read-only in the EMC2106 register set should be loaded with
00h in the EEPROM.
Because of the interaction between the Fan Control Look-up Tables and the Fan Configuration
Register, the EEPROM Loader stores the contents of the Fan Configuration Registers and updates
these registers at the end of the EEPROM loading cycle.
ACK
WR
0
0
The EEPROM slave address must be 1010_000xb. The device must support a block-read
command, 8-bit addressing, and 8-bit data formatting using a 2-wire bus. The device must
support 3.3V digital switching logic and may not pull the SMCLK and SMDATA pins above
5V. Data must be transmitted MSB first.
another SMBus Master will cause errors in reading from the EEPROM.
Data (02h)
Register
ACK
XXh
0
Table 4.8 Block Read Byte Protocol
Register
Address
ACK
00h
0
DATASHEET
Data (03h)
Register
ACK
XXh
23
0
START
0 -> 1
. . .
. . .
ADDRESS
0101_111
SLAVE
ACK
0
RD
Data (FFh)
1
Register
XXh
ACK
0
Revision 1.74 (05-08-08)
Data (00h)
Register
NACK
XXh
1
STOP
1 -> 0
. . .