CURRENT ISSUE
Contests
Feature Article
|
|
Issue #208 November 2007
Analog Techniques
iEthernet Bootcamp
Get Started with the W5100
by Fred Eady
Start | WIZnet W5100 | Build A Development Board | WIZnet W5100 Garage Code| Congratulations! | Sources & PDF
WIZnet W5100
The WIZnet W5100 is a single-IC Ethernet solution with a built-in TCP/IP stack. The W5100 folks like to call their on-chip stack a “hardwired stack” because all of the W5100’s Internet-enabling goodies are contained within a compact 80-pin LQFP. In addition to the W5100’s hardwired TCP/IP stack, other W5100 Ethernet goodies include an integrated IEEE 802.3 10Base-T and 802.3u 100Base-TX-compliant MAC and PHY. As you would expect, the W5100’s TCP/IP stack supports all of the things you need to put an embedded Ethernet gadget on a network. The W5100’s TCP/IP stack supports TCP, UDP, ICMP, and ARP, which normally provide enough protocol power for a major portion of embedded Ethernet LAN and Internet projects that are launched by folks like you and me. PPPoE is also supported by the W5100. The inclusion of PPPoE enables you to use the W5100 in ADSL applications.
If you’ve ever toyed with embedded Ethernet, you know that the lack of a transmit or receive buffer memory can be painful and hamper the performance of your embedded Ethernet device. The embedded Ethernet IC manufacturers are aware of this. Most of the single-IC Ethernet solutions offered these days include a fair amount of dedicated transmit and receive buffer memory. The W5100 is no exception, and it is equipped with 16 KB of internal transmit/receive buffer memory.
To avoid the exclusion of smaller microcontrollers, the W5100 can communicate with a host of microcontrollers using an SPI, direct memory access, or indirect memory access. To further accommodate the majority of today’s newer microcontrollers, the W5100 is powered with a 3.3-VDC power source. This enables the W5100 to be directly interfaced to low-power microcontrollers that also run on a 3.3-VDC power rail. The W5100 can also be integrated into legacy 5-VDC systems because its I/O subsystem is 5-V tolerant.
The W5100 supports up to four simultaneously active sockets. Thus, all you need to know is basic socket programming because you will be shielded from the W5100’s internal Ethernet engine operations. The W5100 is designed to provide the bulk of everything needed to produce a working embedded Ethernet device while being easy to use. The only things the W5100 won’t do for you are write its own code and handle IP fragmentation.
I just happen to have a couple of W5100 ICs. Let’s assemble
a W5100-based device from scratch. Once we’ve got the W5100 hardware realized,
we’ll put together some Microchip Technology PIC18LF8722 driver code for
our W5100 development board.
|
