Rainbow Electronics MAX1618 - Manual (Page 11)

MAX1618
Remote Temperature Sensor
with SMBus Serial Interface
______________________________________________________________________________________ 11
Read remote temperature; returns latest temperature RRTE 01h
00h
COMMAND
0000 0000*
N/A
POR STATE
Read configuration byte RCL 03h
02h
0000 1000
N/A Read status byte (flags, busy signal) RSL
Reserved for future use RFU 05h
Reserved for future use RFU
04h
N/A
0000 0111
Read remote T HIGH limit RRHI 07h
06h
0111 1111
N/A Reserved for future use RFU
Read conversion rate byte (not supported by MAX1618)
REGISTER
RCRA
Write configuration byte WCA 09h
08h
N/A
1100 1001
FUNCTION
Reserved for future use RFU 0Bh
0Ah
N/A
N/A Write conversion rate byte (not supported by MAX1618) WCRW
Write remote T
HIGH
limit WRHA 0Dh
Read remote T LOW limit RRLS
0Ch
N/A
N/A
One-shot command OSHT 0Fh
0Eh
N/A
N/A Write remote T LOW limit WRLN
Reserved for future use RFU
Read device ID code DEVID FFh
FEh
00000010
01001101 Read manufacturer ID code MFGID
*If the device is in hardware-standby mode at POR, the temperature register reads 0°C.
Table 3. Command-Byte Bit Assignments
Table 4. Configuration-Byte Bit
Assignments
RUN/
STOP
6 0
0
POR
STATE
Standby mode control bit. If
high, the device immediately
stops converting and enters
standby mode. If low, the
device converts in either
one-shot or timer mode.
Masks all ALERT interrupts
when high.
FUNCTION
POL 5 0
ALERT pin polarity control in
thermostat mode.
0 = active low
1 = active high
THERM 4 0
Enables thermostat mode
when high.
ID 3 1
MASK
7
(MSB)
Enables diode bias current.
0 (Logic Low) = 5µA to 50µA
(typ)
1 (Logic High) = 10µA to
100µA (typ)
2 to 0 RFU 0 Reserved for future use.
BIT NAME
RFU 6, 5 Reserved for future use (returns 0).
A high indicates that the ADC is busy
converting.
FUNCTION
RHIGH* 4
A high indicates that the remote high-
temperature alarm has activated. In
thermostat mode, this bit is always in
the same state as the ALERT output.
RLOW* 3
A high indicates that the remote low-
temperature alarm has activated. In
thermostat mode, this bit is always
zero.
DIODE 2
A high indicates a remote-diode fault
(open-circuit, shorted diode, or DXP
short to GND).
RFU
1, 0
(LSB)
Reserved for future use (returns 0).
BUSY
7
(MSB)
BIT NAME
Table 5. Status-Byte Bit
Assignments
*In ALERT mode, the HIGH and LOW temperature alarm flags
stay high until cleared by POR or until the status byte register
is read.