MCP9800A0-M/MS MICROCHIP [Microchip Technology], MCP9800A0-M/MS Datasheet - Page 14

• Manufacturer Part Number: MCP9800A0-M/MS
• Description: 2-Wire High-Accuracy Temperature Sensor
• Manufacturer: MICROCHIP [Microchip Technology]

MCP9800/1/2/3
5.3
The MCP9800/1/2/3 has four registers that are
user-accessible. These registers are specified as the
Ambient Temperature (T
Limit-set (T
(T
register.
The Ambient Temperature register is a read-only
register and is used to access the ambient temperature
data. The data from the ADC is loaded in parallel in the
register. The Temperature Limit-set and Temperature
Hysteresis registers are read/write registers that
provide user-programmable temperature limits. If the
ambient temperature drifts beyond the programmed
limits, the MCP9800/1/2/3 outputs an alert signal using
the ALERT pin (refer to
Output
register provides access for the user to configure the
MCP9800/1/2/3’s various features. These registers are
described in further detail in the following sections.
The registers are accessed by sending Register Point-
ers to the MCP9800/1/2/3 using the serial interface.
This is an 8-bit pointer. However, the two Least
Significant bits (LSbs) are used as pointers and all
other bits need to be cleared <0>. This device has addi-
tional registers that are reserved for test and
calibration. If these registers are accessed, the device
may not perform according to the specification. The
pointer description is shown below.
REGISTER 5-1:
DS21909C-page 14
bit 7
Legend:
R = Readable bit
-n = Value at POR
bit 7-2
bit 1-0
.
HYST
U-0
) register and device Configuration (CONFIG)
0
Configuration”). The device Configuration
Registers
SET
) register, the Temperature Hysteresis
Unimplemented: Read as ‘0’
Px<1:0>: Pointer bits
00 = Temperature register (T
01 = Configuration register (CONFIG)
10 = Temperature Hysteresis register (T
11 = Temperature Limit-set register (T
U-0
0
REGISTER POINTER
A
) register, the Temperature
Section 5.3.4.3 “ALERT
W = Writable bit
‘1’ = Bit is set
U-0
0
A
)
U-0
0
SET
HYST
)
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
)
FIGURE 5-2:
U-0
0
Configuration
Temperature
Register
Register
Register
Register
T
T
HYST
SET
Alert Comp/Int
Fault Queue
Alert Polarity
Resolution
Shutdown
One-Shot
U-0
0
Register Block Diagram.
 2010 Microchip Technology Inc.
ALERT Output
Control Logic
x = Bit is unknown
R/W-0
P1
R/W-0
ALERT
Output
P0
bit 0