MAX6604 MAXIM [Maxim Integrated Products], MAX6604 Datasheet - Page 6

• Manufacturer Part Number: MAX6604
• Description: Precision Temperature Monitor for DDR Memory Modules
• Manufacturer: MAXIM [Maxim Integrated Products]

The temperature sensor is accessed through the
SMBus/I
ture sensor address begins with 0011 and is followed
by the logic states of the A2, A1, and A0 inputs. These
inputs must be hardwired to either GND or V
three address inputs set the bus address for the tem-
perature sensor to allow up to eight devices on one
bus. The 8th bit (R/W) dictates a read or write opera-
tion. Set the R/W bit low for a write operation and set
the R/W bit high for a read operation. See Table 1 for a
summary of the device address.
The thermal sensor continuously monitors the tempera-
ture and records the temperature data at least eight
times per second. Temperature data is latched internal-
ly by the MAX6604 and can be read by software from
the bus host at any time.
Access to the temperature sensor is through the slave
ID of 0011-A2-A1-A0. The I
(A2, A1, A0) allow up to eight such devices to coexist
on the same bus. Consequently, eight memory modules
can be supported, given each module has one such
slave device address slot.
Upon application of power, the MAX6604’s configuration
registers are set to their default values. Table 2 lists the
various temperature registers and their default states.
Note that all registers are 16 bits in length.
Precision Temperature Monitor for
DDR Memory Modules
Figure 2. SMBus/I
6
Write Word Format
Read Word Format
S = Start condition
P = Stop condition
_______________________________________________________________________________________
S
S
2
Slave Address: equiva-
lent to chip-select line of
a 3-wire interface
C bus using an 8-bit address. The tempera-
ADDRESS
7 bits
Slave Address: equivalent
to chip-select line of a
3-wire interface
ADDRESS
2
7 bits
C Protocols
Shaded = Slave transmission
R/W = Read/Write
R/W
ACK
R/W
2
C address-selection inputs
Temperature Sensor
Command Byte: selects
to which register you are
writing
COMMAND
8 bits
Device Addressing
ACK
NA = Not acknowledged
Command Byte: selects
to which register you are
writing
ACK = Acknowledge
ACK
COMMAND
CC
8 bits
. The
S
Slave Address: repeated
due to change in data-
flow direction
ADDRESS
ACK
Table 1. MAX6604 Sensor Address
Table 2. MAX6604 Registers
Temperature
ADDRESS
FUNCTION
08h–0Eh
sensor
00h
01h
02h
03h
04h
05h
06h
07h
Data Byte: data goes into the register
set by the co mma nd byte
R
DATA
(MSB)
8 bits
ACK
STATE
004Dh
0017h
0000h
0000h
0000h
0000h
0000h
3E00h
0000h
POR
0
ACK
Data Bytes: reads from
the register set by the
command byte
(MSB)
DATA
8 bits
0
Capability register
Configuration register
Alarm-temperature upper-boundary
trip register
Alarm-temperature lower-boundary
trip register
Critical-temperature trip register
Temperature register
Manufacturer’s ID register
Device ID/revision register
Vendor-defined registers (not used)
DATA
8 bits
(LSB)
1
ACK
ADDRESS
1
DESCRIPTION
ACK
DATA
(LSB)
8 bits
A2
A1
P
NA
A0
P
R/W