PC87413 datasheet(87/257 Pages) NSC

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3.0 Device Architecture and Configuration (Continued)

Revision 1.2

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3.16 REAL TIME CLOCK (RTC) CONFIGURATION

3.16.1

General Description

The RTC provides timekeeping and calendar management capabilities. It uses a 32.768 KHz signal as the basic clock for

timekeeping. The RTC also includes 242 bytes of battery-backed RAM for general-purpose use.

The RTC runtime registers are shown in Section 8.3.2 on page 150. These registers are VPP powered.

3.16.2

Logical Device 10 (RTC) Configuration

Table 30 lists the configuration registers that affect the Real Time Clock. The standard configuration registers (see Section

3.2.3 on page 40) are powered by VDD. The specific configuration registers are powered by VSB.

Table 30. RTC Conﬁguration Registers

Index

RTC Conﬁguration Register or Action

Type

Power Well

Reset

30h

Activate (see Section 3.3.1 on page 43). When bit 0 is cleared, the runtime

registers of this logical device are not accessible.

R/W

VDD

00h

60h

Standard Base Address MSB register.

R/W

VDD

00h

61h

Standard Base Address LSB register. Bit 0 (for A0) is read only 0b.

R/W

VDD

70h

62h

Extended RAM Base Address MSB register.

R/W

VDD

00h

63h

Extended RAM Base Address LSB register. Bit 0 (for A0) is read only 0b.

R/W

VDD

72h

70h

RTC Interrupt Number and Wake-Up on IRQ Enable register.

R/W

VDD

08h

71h

RTC Interrupt Type. Bit 1 is read/write; other bits are read only.

R/W

VDD

00h

74h

Report no DMA assignment.

VDD

04h

75h

Report no DMA assignment.

VDD

04h

F0h

RAM Lock Register (RLR).

R/W1S

VSB

00h

F1h

Date-of-Month Alarm Register Offset (DOMAO).

R/W

VSB

00h

F2h

Month Alarm Register Offset (MONAO).

R/W

VSB

00h

F3h

Century Register Offset (CENO).

R/W

VSB

00h

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