HMS99C5X Series

Jan. 2003 Ver 1.0

9

FUNCTIONAL DESCRIPTION

The HMS99C5X series is fully compatible to the standard 8051 microcontroller family.

It is compatible with the general 8051 family. While maintaining all architectural and operational characteristics

of the general 8051 family.

Figure 1 shows a block diagram of the HMS99C5X series

Figure 1. Block Diagram of the HMS99C5X series

FRASH

4K/8K

RAM

128/256

×8

OSC & TIMING

CPU

Timer 0

Timer 1

Timer 2

Interrupt Unit

Serial Channel

Port 0

Port 1

Port 2

Port 3

Port 0

8-bit Digit. I/O

Port 1

8-bit Digit. I/O

Port 2

8-bit Digit. I/O

Port 3

8-bit Digit. I/O

XTAL1

XTAL2

RESET

ALE/PROG

PSEN