Solution for connecting information appliances to the Internet based on 16-bit single-chip microcomputer

0 Introduction

With the advent of the Internet era, the Internet has become an important basic information facility. The technological progress in this area has had a positive impact on all aspects of society. Many fields are constantly exploring, developing and utilizing network resources. From the current situation, most access methods still use PC as a gateway to connect. However, this situation is generally used in large-scale industrial distributed control systems. If an additional PC is used for general information appliance access, it will inevitably bring high costs to the product, which is not practical from the perspective of product economics. The way to connect information appliances with embedded devices solves this problem well. The so-called embedded devices are generally composed of embedded microprocessors, peripherals, specific network protocols, and applications. They are used to realize remote control, monitoring and management functions of information appliances. They replace traditional PCs or gateway devices, can meet the requirements when the data volume is not large, and have the advantages of reliability, flexibility, and low cost.

1 Proposal

From the perspective of remote online access of information appliances, there are two situations when monitoring and controlling information appliances: (1) During remote access, the communication data volume of information appliances is not large, and a communication rate of 56Kbps can meet the requirements; (2) Information appliances do not have high requirements for real-time performance, and their delay can be more than 1 second. Based on the above two conditions, when selecting embedded devices, the single-chip microcomputer SPCE061A was selected as the microprocessor for information appliances to access the Internet, and RTL8019AS was used as the driver chip for Ethernet frames, which is responsible for receiving and sending Ethernet frames. Finally, the status information is sent to the Internet and the control data is received from the Internet through the RJ45 interface. In addition, to realize the access of information appliances to the Internet, it is also necessary to have a deep understanding of the TCP/IP protocol and the network card driver.

2 Introduction to RTL8019AS Ethernet Controller

The RTL8019AS Ethernet controller produced by Taiwan's REALTEK company occupies a considerable proportion in the 10Mbps network card market due to its excellent performance and low price.

2.1 Main performance

(1) Comply with Ethernet II and IEEE802.3 (10Base5, 10Base2, 10BaseT) standards;

(2) Full-duplex, sending and receiving can reach a rate of 10Mbps at the same time;

(3) Built-in 16KB SRAM for transmit and receive buffering, reducing the speed requirements of the main processor;

(4) Support 8/16-bit data bus, 8 interrupt request lines and 16 I/O base address selections;

(5) Supports automatic detection of UTP, AUI, and BNC, and also supports automatic polarity correction for 10BaseT topology;

(6) Allows 4 diagnostic LED pins to be programmable output;

(7) 100-pin TQFP package reduces PCB size.

The RTL8019AS can be divided into remote DMA interface, local DMA interface, MAC (media access control) logic, data encoding and decoding logic and other ports. Its internal structure is shown in Figure 1.

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0 Introduction

With the advent of the Internet era, the Internet has become an important basic information facility. The technological progress in this area has had a positive impact on all aspects of society. Many fields are constantly exploring, developing and utilizing network resources. From the current situation, most access methods still use PC as a gateway to connect. However, this situation is generally used in large-scale industrial distributed control systems. If an additional PC is used for general information appliance access, it will inevitably bring high costs to the product, which is not practical from the perspective of product economics. The way to connect information appliances with embedded devices solves this problem well. The so-called embedded devices are generally composed of embedded microprocessors, peripherals, specific network protocols, and applications. They are used to realize remote control, monitoring and management functions of information appliances. They replace traditional PCs or gateway devices, can meet the requirements when the data volume is not large, and have the advantages of reliability, flexibility, and low cost.

1 Proposal

From the perspective of remote online access of information appliances, there are two situations when monitoring and controlling information appliances: (1) During remote access, the communication data volume of information appliances is not large, and a communication rate of 56Kbps can meet the requirements; (2) Information appliances do not have high requirements for real-time performance, and their delay can be more than 1 second. Based on the above two conditions, when selecting embedded devices, the single-chip microcomputer SPCE061A was selected as the microprocessor for information appliances to access the Internet, and RTL8019AS was used as the driver chip for Ethernet frames, which is responsible for receiving and sending Ethernet frames. Finally, the status information is sent to the Internet and the control data is received from the Internet through the RJ45 interface. In addition, to realize the access of information appliances to the Internet, it is also necessary to have a deep understanding of the TCP/IP protocol and the network card driver.

2 Introduction to RTL8019AS Ethernet Controller

The RTL8019AS Ethernet controller produced by Taiwan's REALTEK company occupies a considerable proportion in the 10Mbps network card market due to its excellent performance and low price.

2.1 Main performance

(1) Comply with Ethernet II and IEEE802.3 (10Base5, 10Base2, 10BaseT) standards;

(2) Full-duplex, sending and receiving can reach a rate of 10Mbps at the same time;

(3) Built-in 16KB SRAM for transmit and receive buffering, reducing the speed requirements of the main processor;

(4) Support 8/16-bit data bus, 8 interrupt request lines and 16 I/O base address selections;

(5) Supports automatic detection of UTP, AUI, and BNC, and also supports automatic polarity correction for 10BaseT topology;

(6) Allows 4 diagnostic LED pins to be programmable output;

(7) 100-pin TQFP package reduces PCB size.

The RTL8019AS can be divided into remote DMA interface, local DMA interface, MAC (media access control) logic, data encoding and decoding logic and other ports. Its internal structure is shown in Figure 1.

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R1=0x0001; //Select register 00H

[P_IOB_Data]=R1;

R1=0x0021; //Select register page 0, the chip does not work

[P_IOA_Data]=R1;

[P_IOB_Data]=R1;

R1=0x004c; //Set the receive buffer, the page address is 0x4c~0x7f

[P_IOA_Data]=R1;

R1=0x0001; //Select register 02H

[P_IOB_Data]=R1;

R1 = 0x0080;

[P_IOA_Data]=R1;

...

R1=0x0801; //Select register 01H

R1=0x0001; //Select register 00H

[P_IOB_Data]=R1;

R1=0x0061; //Select register page 1

[P_IOA_Data]=R1;

...

R1 = 0x0001;

[P_IOB_Data]=R1;

R1=0x0022; //Select register page 0, the chip enters working state

[P_IOA_Data]=R1;

retf; // program returns

6 Conclusion

By using the 16-bit single-chip microcomputer SPCE061A to drive the Ethernet control chip RTL8019AS, information appliances can be connected to the Internet via an embedded gateway, and the working status of information appliances can be conveniently and cheaply sent to a remote PC for monitoring. This low-cost, high-performance solution is reliable and flexible, and is suitable for home automation devices with low communication rates and delays. Users can use the above method to give traditional home appliances the ability to access the Internet as needed.