DS87C530/DS83C530 EPROM/ROM Microcontrollers with Real-Time Clock

Figure 1. Block Diagram

DS87C530/

DS83C530

PIN DESCRIPTION

 

PIN

NAME

FUNCTION

 

 

 

PLCC

 

TQFP

 

 

 

52

 

45

VCC

+5V Processor Power Supply

1, 25

 

18, 46

GND

Processor Digital Circuit Ground

 

 

 

 

 

29

 

22

VCC2

+5V RTC Supply. VCC2 is isolated from VCC to isolate the RTC from digital noise.

26

 

19

GND2

RTC Circuit Ground

 

 

 

 

 

 

 

 

 

Reset Input. This pin contains a Schmitt voltage input to recognize external active

12

 

5

RST

high reset inputs. The pin also employs an internal pulldown resistor to allow for a

 

combination of wired OR external reset sources. An RC is not required for power-up,

 

 

 

 

 

 

 

 

as the device provides this function internally.

 

 

 

 

 

23

 

16

XTAL2

Crystal Oscillator Pins. XTAL1 and XTAL2 provide support for parallel-resonant,

 

 

 

 

AT-cut crystals. XTAL1 acts also as an input if there is an external clock source in

 

 

 

 

24

 

17

XTAL1

place of a crystal. XTAL2 is the output of the crystal amplifier.

 

 

 

 

 

4 of 47