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SMARTWATCH REGISTER INFORMATION

The SmartWatch information is contained in eight registers of 8 bits, each of which is sequentially

accessed one bit at a time after the 64-bit pattern recognition sequence has been completed. When

updating the SmartWatch registers, each must be handled in groups of 8 bits. Writing and reading

individual bits within a register could produce erroneous results. These read/write registers are defined in

Figure 3.

Data contained in the SmartWatch registers is in binary-coded decimal format (BCD). Reading and

writing the registers is always accomplished by stepping through all eight registers, starting with bit 0 of

register 0 and ending with bit 7 of register 7.

AM–PM/12/24 MODE

Bit 7 of the hours register is defined as the 12-hour or 24-hour mode-select bit. When high, the 12-hour

mode is selected. In the 12-hour mode, bit 5 is the AM/PM bit with logic high being PM. In the 24-hour

mode, bit 5 is the second 10-hour bit (20–23 hours).

OSCILLATOR AND RESET BITS

RESET

changing data in the watch registers. Bit 5 controls the oscillator. When set to logic 1, the oscillator is off.

When set to logic 0, the oscillator turns on and the watch becomes operational. These bits are shipped

from the factory set to logic 1.

ZERO BITS

Registers 1, 2, 3, 4, 5, and 6 contain one or more bits that will always read logic 0. When writing these

locations, either a logic 1 or 0 is acceptable.

ADDITIONAL INFORMATION

Refer to Application Note 52 for information about using regarding optional modifications and the

phantom clock contained within the SmartWatch.