MCP9803 datasheet(9/30 Pages) MICROCHIP

9 / 30 page

 2004 Microchip Technology Inc.

DS21909B-page 9

MCP9800/1/2/3

4.3

Registers

The MCP9800/1/2/3 family has four registers that are

user-accessible. These registers are specified as the

ambient temperature register, the temperature limit-set

configuration registers.

The ambient temperature register is a read-only

data. The data from the ADC is loaded in parallel in the

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 Section 4.3.4.3 “ALERT Out-

put Configuration”). The device configuration 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.

FIGURE 1:

The registers are accessed by sending register pointer

to the MCP9800/1/2/3 using the serial interface. This is

an 8-bit pointer. However, the two Least Significant bits

(LSb) are used as pointers and all other bits need to be

cleared <0>. This device has additional 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.

ALERT Output

Control Logic

ALERT

Output

Resolution

Temperature

THYST

TSET

Configuration

One-Shot

Shutdown

Fault Queue

Alert Polarity

Alert Comp/Int

U-0

R/W-0

bit 7

bit 0

bit 7-3

Unimplemented: Read as ‘0’

bit 2-0

Pointer bits

Temperature Register

Configuration Register

Temperature Hysteresis Register

Temperature Limit-set Register

Legend:

R = Readable bit

W = Writable bit

U = Unimplemented bit, read as ‘0’

- n = Value at POR

‘1’ = Bit is set

‘0’ = Bit is cleared

x = Bit is unknown

MCP9803 Datasheet(PDF) 9 Page - Microchip Technology

MCP9803 Datasheet(HTML) 9 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

Datasheet Download

Link URL