DS1248 Maxim, DS1248 Datasheet - Page 7

• Manufacturer Part Number: DS1248
• Description: The DS1248 1024K NV SRAM with Phantom Clock is a fully static nonvolatile RAM (organized as 128K words by 8 bits) with a built-in real-time clock
• Manufacturer: Maxim

DS1248/DS1248P 1024K NV SRAM with Phantom Clock
Figure 2. Phantom Clock Register Definition
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 20-hour bit (20–23 hours).
OSCILLATOR AND RESET BITS
Bits 4 and 5 of the day register are used to control the RST and oscillator functions. Bit 4 controls the
RST (pin 1). When the RST bit is set to logic 1, the RST input pin is ignored. When the RST bit is set to
logic 0, a low input on the RST pin will cause the phantom clock to abort data transfer 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.
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