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Main device (continued) – Rainbow Electronics DS1857 User Manual

Page 13

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DS1857

Dual Temperature-Controlled Resistors with

External Temperature Input and Monitors

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13

MEMORY

LOCATION

(hex)

EEPROM/

SRAM

R/W

DEFAULT

SETTING

(hex)

NAME OF LOCATION

FUNCTION

1C to 5F

EEPROM

00

Reserved

60 to 61

SRAM

R

Measured TMP

(MSB to LSB)

Digitized measured value for temperature.
See Table 1.

62 to 63

SRAM

R

Measured V

CC

(MSB to LSB)

Digitized measured value for V

CC

.

See Table 1.

64 to 65

SRAM

R

Measured MON1

(MSB to LSB)

Digitized measured value for MON1.
See Table 1.

66 to 67

SRAM

R

Measured MON2

(MSB to LSB)

Digitized measured value for MON2.
See Table 1.

68 to 6D

SRAM

R

Reserved

6E

SRAM

Logic states

Bit 7

R

X

HIZSTA

Resistor status bit. A high indicates that both
resistors are in high-impedance mode. A low
indicates that both resistors are operating
normally.

6

R/W

0

HIZCO

Resistor control bit. Setting this bit high
causes both resistors to go into a high-
impedance state.

5

X

X

4

X

X

3

X

X

2

X

X

1

X

X

0

R

X

RDYB

This status bit goes high when V

CC

has fallen

below the POA level.

6F

SRAM

Conversion updates

Bit 7

R/W

0

TAU

This bit goes high after a temperature and
address update has occurred for the
corresponding measurement in bytes 60h to
61h. This bit can be written to a 0 by the user
and monitored to verify that a conversion has
occurred.

Main Device (continued)