DS1073
Figure 10
PROGRAMMING
Normally when power is applied to the supply voltage pin the device will enter its normal operating mode
following the power-on reset sequence. However the device can be made to enter a programming mode if
a pullup resistor is connected between I/O and the supply voltage pin, prior to power-up. The method
ꢀ
used for programming is a variant of the 1-Wire protocol used on a number of Dallas Semiconductor
products.
HARDWARE
The hardware configuration is shown in the diagram. A bus master is used to read and write data to the
DS1073’s internal registers. The bus master may have either an open drain or TTL-type architecture.
Figure 11
Programming mode is entered by simply powering up the DS1073 with a pullup of approximately 5kꢀ.
This will pull the I/O pin above VIH on power-up and initiate the programming mode, causing the
DS1073 to internally release the I/O pin (after tPOR), and allow the pullup resistor to pull the pin to the
supply rail and await the Master Tx Reset pulse (see diagram).
10 of 18
DALLAS [ DALLAS SEMICONDUCTOR ]
