Datasheet

MCP9843/98243
DS22153C-page 18 © 2009 Microchip Technology Inc.
5.1.1 CAPABILITY REGISTER
This is a read-only register used to identify the
temperature sensor capability. For example, the
MCP9843/98243 device is capable of providing
temperature at 0.25°C resolution, measuring
temperature below and above 0°C, providing ±1°C and
±2°C accuracy over the active and monitor temperature
ranges (respectively) and providing user-
programmable temperature event boundary trip limits.
Register 5-2 describes the Capability register. These
functions are described in further detail in the following
sections.
REGISTER 5-2: CAPABILITY REGISTER (READ-ONLY) → ADDRESS ‘0000 0000’b
U-0 U-0 U-0 U-0 U-0 U-0 U-0 U-0
————————
bit 15 bit 8
R-1 R-1 R-1 R-0 R-1 R-1 R-1 R-1
SHDN Status t
OUT
Range V
HV
Resolution Meas Range Accuracy Temp Alarm
bit 7 bit 0
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
bit 15-8 Unimplemented: Read as ‘0’
bit 7 Event output status during Shutdown (SHDN Status):
0 = Event output remains in previous state. If the output asserts before shutdown command, it
remains asserted during shutdown.
1 = Event output de-asserts during shutdown. After shutdown, it takes t
CONV
to re-assert the Event
output (power-up default)
bit 6 I
2
C Bus time-out (t
OUT
Range):
0 = Bus time-out range is 10 ms to 60 ms
1 = Bus time-out range is 25 ms to 35 ms (power-up default)
bit 5 High Voltage Input
0 = Pin A0 does not accept High Voltage
1 = Pin A0 accepts High Voltage for the EEPROM Write Protect feature (power-up default)
bit 4-3 Resolution:
00 = 0.5°C
01 = 0.25°C (power up default)
10 = 0.125°C
11 = 0.0625°C
These bits reflect the selected resolution (see Section 5.2.4 “Temperature Resolution”)
bit 2 Temperature Measurement Range (Meas. Range):
0 =T
A
= 0 (decimal) for temperature below 0°C
1 = The part can measure temperature below 0°C (power-up default)