Rainbow Electronics DS1616 User Manual

Page 4

DS1616

4 of 28

Tx (Transmit Output) - Transmit output of the asynchronous serial interface. Tx is tri-stated whenever
V

< V

bat

Rx (Receive Input) - Receive input of the asynchronous serial interface.

SCLK (3-Wire Serial Clock Input) - The SCLK pin is the serial clock input for the 3-wire synchronous
communications channel.

I/O (3-Wire Input/Output) - The I/O pin is the data Input/Output signal for the 3-wire synchronous
communications channel.

RST

(3-Wire Reset Input) - The

RST

pin is the communications reset pin for the 3-wire synchronous

communications channel.

(Interrupt Output) - The

INT

pin is an open drain active low output that can be connected to an

interrupt input of a microprocessor. The

INT

output remains low as long as the status bit causing the

interrupt is present and the corresponding interrupt-enable bit is set.

INSPEC

(Open Drain In-Specification Output) - This pin, in conjunction with the

OUTSPEC

pin, is

used to signal the status of the operation and data of the DS1616.

OUTSPEC

(Open Drain Out-of-Specification Output) - This pin, in conjunction with the

INSPEC

pin,

is used to signal the status of the operation and data of the DS1616.

(Start/Status Button Input) - The

pin provides two functions. First, when enabled as the datalog

start source (SE bit in Control 1 register is a logic 1), the

pin is used to instruct the DS1616 to begin

recording data based on the programmed start delay and data sample rate. The

pin must be held low

for at least 0.5 seconds for a datalog mission to begin.

Secondly, the

pin can be used to poll the status of the recorded data. After datalogging has begun, the

pin instructs the DS1616 to report the status of the recorded data via the

INSPEC

and

OUTSPEC

pins.

AIN1, AIN2, AIN3 (Analog Inputs) - The AINx pins are the muxed inputs to the ADC.

X1, X2 - Connections for a standard 32.768 kHz quartz crystal, Daiwa part number DT-26S or
equivalent. For greatest accuracy, the DS1616 must be used with a crystal that has a specified load
capacitance of 6 pF. There is no need for external capacitors or resistors. Note: X1 and X2 are very high
impedance nodes. It is recommended that they and the crystal be guard-ringed with ground and that high
frequency signals be kept away from the crystal area. For more information on crystal selection and
crystal layout considerations, refer to Application Note 58: Crystal Considerations with Dallas Real-Time
Clocks.

N.C. (No Connect) - These pins should be left unconnected or tied to ground.