MAX1668_00 Datasheet, PDF (12/16 Pages) Maxim Integrated Products – Multichannel Remote/Local Temperature Sensor

Multichannel Remote/Local
Temperature Sensor
Command Byte Functions
The 8-bit command byte register (Table 4) is the master
index that points to the various other registers within the
MAX1668/MAX1805. The register’s POR state is 0000
0000, so that a Receive Byte transmission (a protocol
that lacks the command byte) that occurs immediately
after POR returns the current local temperature data.
Manufacturer and Device ID Codes
Two ROM registers provide manufacturer and device
ID codes. Reading the Manufacturer ID returns 4Dh,
which is the ASCII code M (for Maxim). Reading the
device ID will return 03h for MAX1668, and 05h for
MAX1805. If Read Word 16-bit SMBus protocol is
Table 4. Command Byte Bit Assignments for MAX1668/MAX1805
REGISTER
RIT
RET1
RET2
RET3**
RET4**
RS1
RS2
RC
RIHL
RILL
REHL1
RELL1
REHL2
RELL2
REHL3**
RELL3**
REHL4**
RELL4**
WC
WIHL
WILL
WEHI1
WELL1
WEHI2
WELL2
WEHI3**
WELL3**
WEHI4**
WELL4**
MFG ID
DEV ID
COMMAND
00h
01h
02h
03h
04h
05h
06h
07h
08h
09h
0Ah
0Bh
0Ch
0Dh
0Eh
0Fh
10h
11h
12h
13h
14h
15h
16h
17h
18h
19h
1Ah
1Bh
1Ch
FEh
FFh
POR STATE
0000 0000*
0000 0000*
0000 0000*
0000 0000*
0000 0000*
0000 0000
0000 0000
0000 0000
0111 1111
1100 1001
0111 1111
1100 1001
0111 1111
1100 1001
0111 1111
1100 1001
0111 1111
1100 1001
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
0100 1101
0000 0011 (0000 0101)
FUNCTION
Read local temperature
Read remote DX1 temp.
Read remote DX2 temp.
Read remote DX3 temp.
Read remote DX4 temp.
Read status byte #1
Read status byte #2
Read Configuration Byte
Read local T_HIGH limit
Read local T_LOW limit
Read remote DX1 T_HIGH limit
Read remote DX1 T_LOW limit
Read remote DX2 T_HIGH limit
Read remote DX2 T_LOW limit
Read remote DX3 T_HIGH limit
Read remote DX3 T_LOW limit
Read remote DX4 T_HIGH limit
Read remote DX4 T_LOW limit
Write configuration byte
Write local T_HIGH limit
Write local T_LOW limit
Write remote DX1 T_HIGH limit
Write remote DX1 T_LOW limit
Write remote DX2 T_HIGH limit
Write remote DX2 T_LOW limit
Write remote DX3 T_HIGH limit
Write remote DX3 T_LOW limit
Write remote DX4 T_HIGH limit
Write remote DX4 T_LOW limit
Read manufacture ID
Read device ID (for MAX1805)
*If the device is in hardware standby mode at POR, all temperature registers read 0°C.
**Not available for MAX1805.
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