DP8572AMD/883 NSC [National Semiconductor], DP8572AMD/883 Datasheet - Page 8

• Manufacturer Part Number: DP8572AMD/883
• Description: Real Time Clock (RTC)
• Manufacturer: NSC [National Semiconductor]

Functional Description
The DP8572A contains a fast access real time clock inter-
rupt control logic power fail detect logic and CMOS RAM
All functions of the RTC are controlled by a set of seven
registers A simplified block diagram that shows the major
functional blocks is given in Figure 1
The blocks are described in the following sections
1 Real Time Clock
2 Oscillator Prescaler
3 Interrupt Logic
4 Power Failure Logic
5 Additional Supply Management
FIGURE 2 DP8572A Internal Memory Map
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The memory map of the RTC is shown in the memory ad-
dressing table The memory map consists of two 31 byte
pages with a main status register that is common to both
pages A control bit in the Main Status Register is used to
select either page Figure 2 shows the basic concept
Page 0 contains all the clock timer functions while page 1
has scratch pad RAM The control registers are split into
two separate blocks to allow page 1 to be used entirely as
scratch pad RAM Again a control bit in the Main Status
Register is used to select either control register block
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