Rainbow Electronics DS1846 - Manual (Page 3)

DS1846
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PIN DESCRIPTIONS
V
CC
- Power Supply Terminal. The DS1846 will support supply voltages ranging from +2.7 to
+5.5 volts.
GND - Ground Terminal.
SDA - 2-wire serial data interface. The serial data pin is for serial data transfer to and from the DS1846.
The pin is open drain and may be wire-ORed with other open drain or open collector interfaces.
SCL - 2-wire serial clock interface. The serial clock input is used to clock data into the DS1846 on rising
edges and clock data out on falling edges.
WP - Write Protect. Write Protect must be connected to GND before either the data in memory or
potentiometer wiper settings may be changed. Write Protect is pulled high internally and must be either
left open or connected to Vcc if write protection is desired.
A0 - Address Input. This input pin specifies the address of the device when used in a multi-dropped
configuration. Up to two individual DS1846s may be addressed on a single 2-wire bus.
H0, H1, H2 – These are the high-end terminals of the potentiometers. For the three potentiometers, it is
not required that these terminals be connected to a potential greater than the low-end terminal of the
potentiometer. Voltage applied to the high end of the potentiometers cannot exceed the power supply
voltage, V
CC
, or go below ground.
L0, L1, L2 – These are the low-end terminals of the potentiometers. It is not required that these
terminals be connected to a potential less than the high-end terminals of the pot. Voltage applied to the
low end of the potentiometers cannot exceed the power-supply voltage, V
CC
, or go below ground.
W0, W1, W2 - Wiper of the potentiometer. This pin is the wiper terminal of the potentiometer. Three
bytes in EEPROM memory locations F8h, F9h and FAh determine each wiper’s setting. Voltage applied
to either wiper terminal cannot exceed the power-supply voltage, V
CC
, or go below ground.
PBRST – Push button reset. This input pin is active low. It acts as the push button reset pin for the
MicroMonitor.
NMI – Non-maskable interrupt. Active low signal that is generated in order to provide for an early power
fail warning.
IN – NMI voltage input.
RST - Active Low Reset Output. This signal provides an output that can be used to reset a
microprocessor.
RST - Active High Reset Output. This signal provides an output that can be used to reset a
microprocessor.