Implementation of IC card meter based on 68HC908GP32

　　As an IC card billing system , this design uses one of Motorola Semiconductor's new 08 series microcontrollers - 68HC908GP32.

　　2 System Introduction

　　This system uses the Motorola 68HC908GP32 single-chip microcomputer to control the IC card reader to read the data in the IC card, and then after analyzing the signal from the external sensor, it commands the IC card reader to read and write the IC card accordingly, thereby completing the function of a meter. The Motorola single-chip microcomputer is the core of the entire system. The system block diagram is shown in Figure 1.

　　3 68HC908GP32 microcontroller

　　This design uses the GP32 microcontroller, which is a general-purpose chip in Motorola's new 08 series microcontrollers. It has the advantages of fast speed, powerful functions and low price, and is backward compatible with the original M68HC05 series microcontrollers, which greatly protects the interests of users. In addition, the new generation of M68HC08 series models have different sizes of on-chip flash (FLASH) memory according to various models, which has a very high cost performance. According to different applications, the 08 series microcontrollers are divided into many models, and the MC68HC908GP32 microcontroller used in this design adds enhanced serial communication interface SCI and serial peripheral interface SPI on the basis of the standard 08 microcontroller core.

　　The main features of the MC68HC908GP32 microcontroller are:

　　1. 32K on-chip FLASH program memory with online programming capability and confidentiality function.

　　2. 512 bit on-chip RAM

　　3.8MHz internal bus frequency.

　　4. Enhanced serial communication port SCI