emc2101 Standard Microsystems Corp., emc2101 Datasheet - Page 17

• Manufacturer Part Number: emc2101
• Description: Emc2101 Fan Control With 1?c Accurate Temperature Monitoring
• Manufacturer: Standard Microsystems Corp.

SMBus Fan Control with 1°C Accurate Temperature Monitoring
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 EMC2101
START
ACK
1
1
ADDRESS
Data (00h)
Register
SLAVE
7
8
Note: The shaded columns represent data sent from the EMC2101 to the EEPROM device.
The EEPROM should be loaded to mirror the register set of the EMC2101 with the desired
configuration set. All undefined registers in the EMC2101 register set should be loaded with 00h in the
EEPROM. Likewise, all registers that are read-only in the EMC2101 register set should be loaded with
00h in the EEPROM.
Because of the interaction between the Fan Control Look-up Table and the Fan Configuration Register,
the EEPROM Loader stores the contents of the Fan Configuration Register and updates this register
at the end of the EEPROM loading cycle. (See
ACK
WR
1
1
The EEPROM slave address must be 101_0000b. 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 (01h)
Register
ACK
1
8
Table 4.7 Block Read Byte Protocol
Register
Address
ACK
8
1
DATASHEET
Data (02h)
Register
ACK
17
1
8
Section 6.16
START
. . .
. . .
1
ADDRESS
and
SLAVE
ACK
7
1
Section
RD
Data (FFh)
1
Register
6.22).
8
ACK
1
Revision 2.53 (02-19-08)
Register
NACK
Data
8
1
STOP
. . .
. . .
1