DP8570 NSC [National Semiconductor], DP8570 Datasheet - Page 6

• Manufacturer Part Number: DP8570
• Description: Timer Clock Peripheral (TCP)
• Manufacturer: NSC [National Semiconductor]

Functional Description
The DP8570A contains a fast access real time clock two 10
MHz 16-bit timers interrupt control logic power fail detect
logic and CMOS RAM All functions of the TCP are con-
trolled by a set of nine 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
6 Timers
FIGURE 2 DP8570A Internal Memory Map
6
The memory map of the TCP 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
TL F 8638 – 4