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Figure 24.0 Register Set 1 Tab

The “Register Set 2” tab (see Figure 25.0) allows the user

access to the Configuration Register functions as well as

the Slope and Counter registers. This screen also allows

for automatic enabling and disabling of the oscillator

output, as well as providing access to the Clock Alarm and

SRAM registers.

Read Config.- By clicking the button a timer is activated

which immediately sets the command button caption to

“Read Loop On” and performs a continuous read of the

MSB and LSB of Configuration Register.

Write Config.- Each click this button will cause a one-time

write to the MSB of the Configuration Register. Write

commands to the LSB portion of the Configuration Register

are not allowed because the LSB provides only status

information and writing data to the LSB can and will cause

problems in device command interpretation.

Read

Slope-

The

Slope

register

returns

the

COUNT_PER_C value when this button is clicked.

Read Counter- The Counter register returns the

COUNT_REMAIN value when this button is clicked.

Enable Oscillator- The OSC1 and OSC0 bits in the

Configuration Register are both set high when this button

is clicked.

Disable Oscillator- The OSC1 and OSC0 bits in the

Configuration Register are both set low when this button is

clicked.

Read Alarm- By clicking this button, all four DS1629 clock

alarms registers are read into the text boxes located

directly below the “Read Alarm” command button.

Write Alarm- When the user has entered the desired alarm

data into each of the four clock alarm registers located

directly below the command button, the “Write Alarm”

button may be clicked to write the alarm setting into the

device. The settings are automatically read back under the

“Read Alarm” column.

Figure 25.0 Register Set 2 Tab

Read SRAM- Upon program start-up, the SRAM address

pointer is set to location “00”. The user may enter into the

address text box “00” to “1F”. Since there are only 32 bytes

of SRAM space, if the user reads from an address higher

than “1F” the SRAM address pointer will automatically

wrap

around back into the 32 byte address space

available.

Write SRAM- The user may enter any hex address in the

specified 32 byte range along with any byte wide hex data

in the appropriate text box. When the user clicks the “Write

SRAM” button, the data is written to the specified address.

Figure 26.0 provides a block diagram that illustrates the

internal functions of the DS1629. There are eleven major

functional areas in addition to the crystal and oscillator

divider circuits. In a typical application, the 2-wire circuitry

will interface to a CPU. The “Address and I/O Control”

block provides read/write access to the internal registers.

The “Temperature Sensor” interfaces to the “Thermal

Register” and the “Thermal Alarm” register. The thermal

registers interface to the “Thermal Alarm Comparator” and

the “Alarm Select” circuitry.