DS1243 Maxim, DS1243 Datasheet - Page 6

• Manufacturer Part Number: DS1243
• Description: The DS1243Y 64K NV SRAM with Phantom Clock is a fully static nonvolatile RAM (organized as 8192 words by 8 bits) with a built-in real time clock
• Manufacturer: Maxim

DS1243Y
PHANTOM CLOCK REGISTER DEFINITION Figure 2
AM-PM/12/24 MODE
Bit 7 of the hours register is defined as the 12- 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 20-hour bit (20–23 hours).
OSCILLATOR AND RESET BITS
Bits 4 and 5 of the day register are used to control the
and oscillator functions. Bit 4 controls the
RESET
(pin 1). When the
bit is set to logic 1, the
input pin is ignored. When the
RESET
RESET
RESET
RESET
bit is set to logic 0, a low input on the
pin will cause the Phantom Clock to abort data transfer
RESET
without 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 a logic 1, oscillator off.
ZERO BITS
Registers 1, 2, 3, 4, 5, and 6 contain one or more bits that always read logic 0. When writing these
locations, either a logic 1 or 0 is acceptable.
6 of 14