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Run RABBIT Run Rabbits usually have long ears, four legs, lots of fur and can run very fast. This earless rabbit has 100 legs, no fur and runs much faster than a Z180 microprocessor. So is this some form of super mutant rabbit? Nope – it’s a microprocessor that runs rings around the old Z180 but uses an updated Z180-style instruction set to make things easy for ex­perienced Z80/Z180 assembly language programmers. If you can program a Z180, you can program this baby! – or should that be bunny? Going back in time, the Rabbit 2000 Microprocessor was first let out of its hutch by Rabbit Semiconductor in the US in 1999 and immediately spread out, recently arriving Down Under after a long swim across the Pacific. It’s a robust little crit­ter that’s completely unaffected by the Calisi virus and is supported by several very impressive development kits that in­ clude the Dynamic C programming language. And no, that’s not a trial version The RCM2100 Ethernet Core module includes both the Rabbit microcontroller and a Realtek RTL8019AS ethernet IC. You can talk to this unit directly via a LAN or via the Internet. 6  Silicon Chip of Dynamic C – it’s a fully-working version that’s supplied with the core modules and the development kits. What’s in the burrow? There’s more than one Rabbit running around in this warren. Apart from the Rabbit 2000 microprocessor itself, there’s also the Rabbit 2000 and RabbitCore 2000 development kits; the Rabbit­Core RCM 2100 & 2200 Ethernet Core modules; the two development kits associated with these core modules; plus a host of other Rabbit-based products, including the “Jackrabbit” development board, the “RabbitLink” card and the “Rabbit Cloning Board”. The “RabbitLink” card lets you program and debug your Rabbit-based system via a network or the Internet – see Fig.1. What’s more, an inbuilt miniature web server and SMTP client can be controlled by any embedded system via the RabbitLink’s serial port. This allows the system to send information to the network using either email or easily-updated static HTML pages. Want to breed Rabbits? – the Rabbit Cloning Board lets you do just that. It www.siliconchip.com.au copies compiled software programs from one Rabbit 2000-based board to another without the need for a PC. Rabbit stew The main ingredient in the Rabbit stew is, of course, the Rabbit 2000 microprocessor. This is a high-performance, 8-bit microprocessor with a “C-friendly” instruction set, fast number crunching ability and numerous on-chip peripherals. It boasts four serial ports, a slave port, remote bootstrap capability, advanced clocking options (five 8-bit timers & two 10-bit timers), and “glueless” interfacing to both memory and I/O – making hardware design easy. (Note: “glueless interfacing” means that all the interface logic is built into the microprocessor). This Rabbit is fast, with clock speeds up to 30MHz. And because it’s optim­ised for a C-oriented instruction set, the 8-bit Rabbit 2000 is claimed to be a viable alternative to existing 16-bit and 32-bit processors in many situations but at a much lower cost. It runs about three times faster than the Z180 for the same memory speed when running C code. In practice, you can load up to 50,000 or more lines of Dynamic C into the Rabbit’s 1MB of code space. The Dynamic C provides an interactive compiler, editor and source-level debug­ ger and eliminates the need for external emulator hardware. Numerous application libraries are also The RabbitCore RCM2100 Developer’s Kit includes an RCM2100 Ethernet core module with 512KB of flash memory and 512KB of static RAM; a prototyping board; an RS232 programming cable (10-pin header to DB9); a Dynamic C SE CD-ROM (includes royalty-free TCP/IP stack with source plus complete product documentation); a plugpack power supply; and a “Getting Started Manual”. included, thereby short­ening development time and making programming easier. The instruction set The Rabbit 2000 features an updated Z180-style architecture for improved performance. At the same time, a number of obsolete Z180 instructions have been dropped to allow efficient 1-byte operation codes for new instructions. This means that existing Z180 assembly language programs can be ported to the Rabbit 2000 with minimal changes. New “C-friendly” instructions are included for fetching and storing 16bit words located at a computed memory address or on the stack. These new instructions perform fetches, stores, calls, returns and jumps over a full megabyte of address space. The new instructions are claimed to improve communication between Programming The Rabbit With Dynamic C The supplied Dynamic C for the Rabbit 2000 includes a powerful editor, compiler, linker, loader and debugger, along with hundred of functions in source-code libraries. In fact, compiling, linking and loading are all one func­tion. Dynamic C does not use an in-circuit emulator (ICE) – instead, programs being developed are downloaded to and “executed” from the “target” system via the serial port connection. This makes for faster program development and debugging of errors. Breakpoints, single stepping, observation of variables in a running program, complex watch expressions and “printf” com­ mands to the Dynamic C console are all supported www.siliconchip.com.au to aid debug­ging. Other features of Dynamic C include: (1) An easy-to-use inbuilt text editor. Programs can be executed and debugged interactively at sourcecode or machine-code level. Pull down menus and keyboard shortcuts for most commands help make Dynamic C easy to use. (2) Dynamic C supports assembly language programming and it is not necessary to leave C or the development system to write assembly language code. In addition, both C and assembly language can be mixed together. (3) Dynamic C provides extensions to the C language (such as shared and protected variables, co-state- ments and co-functions) that support real-world embedded system development. Interrupt service routines can be written in C and both cooperative and pre-emptive multitasking are supported. (4) Dynamic C is supplied with many function libraries, all in source code. These libraries support real-time programming and machine level I/O and provide string and maths functions. (5) Dynamic C can be compiled directly to memory. Functions and libraries and compiled, linked and downloaded on the fly. On a fast PC, Dynamic C can load 30,000 bytes of code in five seconds at a baud rate of 115,500 bps. October 2001  7 the registers, effectively enlarging the register set. Other new instructions provide 16-bit logical and arithmetic operations. Software floating point routines for add, subtract and multiply require less than 12µs at maximum clock speed. An interesting feature is that memory access instructions can be turned into I/O access instructions by using a prefix. As a result, I/O access is faster and more flexible than on the Z180. Battery backup The Rabbit 2000 has a special support feature for battery-backed RAM. At the same time, a hardware memory write-protect feature protects battery-backed RAM and flash memory from inadvertent write operations. TCP/IP RABBIT LINK On-chip peripherals SERIAL DATA RCM2100 CORE MODULE RJ45 Fig.1: the Rabbit Link interface module lets you program the RCM2100 Core Module directly via a LAN or via the Internet. Programming Point-to Point Protocol (PPP) If you want an embedded system to use the Internet for communications, PPP (Point-to-Point Protocol) is required. Included as an extension to the stand Rabbit 2000 TCP/IP stack, PPP provides the connection to an Internet Service Provider (ISP). The PPP source code is included in Dynamic C Premier (an extra-cost upgrade from Dynamic C SE). One of the most common uses of PPP is the transfer of IP packets 8  Silicon Chip between a remote host and an ISP over a modem connection. The interface between the Rabbit 2000 controller and the modem is either a true RS232 interface or a variation on RS232 that uses TTL voltage levels for the signals. The Rabbit implementation for PPP uses serial port C on the Rabbit chip. Hardware flow control is implemented and follows the RS-232 convention of using the RTS and CTS lines. There are more on-chip peripherals on this Rabbit than fleas on its furry namesake. The accompanying panel shows you what’s there but we’ll list them anyway. There’s a slave interface which allows the Rabbit 2000 to be treated as an intelligent peripheral de­vice; remote bootstrap (so that it can be remotely cold-booted via a serial or parallel slave port); four serial ports plus 40 I/O pins grouped as five 8-bit ports; a low-power “sleep” mode for battery-powered applications; an onboard oscillator based on a standard 32.768kHz crystal; and six timers (four 8-bit and two 10-bit, as mentioned previously). Up to six static memory ICs can be hung off the Rabbit via those 40 I/O lines, without the need for interfacing logic. Take a look at the accompanying panel if you want more information on these on-chip peripherals. Rabbit on Ethernet OK, now that we’ve looked at the www.siliconchip.com.au The Rabbit’s On-Chip Peripherals Slave interface: the slave port allows the Rabbit 2000 to be treated as an intelligent peripheral device. The slave port has six I/O reg­isters, three of each direction. Handshaking flags and mutual interrupt capability are supported. Remote bootstrap: the Rabbit 2000 may be remotely booted by an external device via a serial port or slave port with no pre-existing pro­ gram. This allows complete re­programming of soldered-in flash memory. It also allows RAM-only configurations with external boot and program initialisation. I/O interface and ports: there are 40-plus I/O pins grouped in five 8-bit ports. Eight external programmable I/O interface signals can be config­ ured as I/O chip selects, I/O write strobes, I/O read strobes and I/O read/write strobes. Standard I/O read and I/O write enable signals are also available. I/O devices can be directly connected to the I/O interfaces, and often without glue logic. Four asynchronous serial ports are on-chip. Two of the ports also have synchronous communication capability. The asyn­chronous ports operate at speeds up to 1/32 of the clock frequen­cy, while synchronous mode allows baud rates up to 1/8th of the clock frequency. Low power sleepy mode: a unique sleepy mode of operation is available on the Rabbit 2000. Normally, the main oscillator is implemented by directly connecting a crystal or ceramic resonator with a fre­quency in the range of 1.8-30MHz. The frequency can be double of divided by eight internally to modulate power consumption and speed of execution. In sleepy mode, the main oscillator is turned off and the main clock is taken from the Rabbit’s 32.768kHz oscillator. Roughly 3000 instructions per second can be executed with a current consumption of around 200µA. The sleepy mode is far more flexible than sleep modes of other microprocessors because instruction execution and decision making capability are maintained. This feature is excellent for many battery-powered applications. Clock speed: the Rabbit 2000 performs 1-byte reads (and most 1-byte operations) in two clock cycles, and 1-byte writes in three clock cycles. It requires 55ns memory to operate at 30MHz with no wait states.The Rabbit 2000 runs at 24MHz with 70ns flash memory and no wait states. Time/date oscillator: the 32.678kHz oscillator uses an external quartz crystal. This 32.768kHz clock is used to drive a battery-backable internal 48-bit counter or real-time clock. Timers: the Rabbit 2000 has two sets of timers, as well as a gener­al purpose clock interrupt. The periodic interrupt is driven by the 32.768kHz oscillator divided by 16, giving an interrupt every 488 microseconds if enabled. Timer A consists of five 8-bit reloadable down counters. The output of flour of the timers is used to provide baud clocks for the serial ports. These timers can also cause interrupts and clock the timer synchronized parallel output ports. Timer B consists of a 10-bit free running counter and con­ tains two 10-bit match registers. The timer generates an output pulse whenever the counter reaches the match value. This output pulse can be programmed to generate an interrupt. Silicon Chip Binders REAL VALUE AT $12.95 PLUS P&P  Heavy board covers with 2-tone green vinyl covering Rabbit’s innards, let’s take a look at the RCM 2100/2200 Ethernet Core Modules and the development kits. Ethernet? – you bet your furry ears. You can plug a Rabbit­Core module directly into a standard computer network and “talk” to it via your LAN. Alternatively, you can connect www.siliconchip.com.au it directly to your PC’s network card using a crosso­ver cable. You can even program the Rabbit via a LAN, using the RabbitLink interface card (Fig.1). So how do they get it to talk to a network? Simple – by incorporating a Realtek RTL8019AS Ethernet IC directly onto the module. This  Each binder holds up to 14 issues Price: $A12.95 plus $A5 p&p each (Australia only) Just fill in & mail the handy order form in this issue; or fax (02) 9979 6503; or ring (02) 9979 5644 & quote your credit card number. October 2001  9 allows any faults to be remotely corrected. It can also serve as a portal for downloading updated soft­ware to the main system. Developer’s kits Fig.2: the Dynamic C development environment. Shown here are the main editing window, the assembly code window, the register window, the stack window and the watch window (which lets you watch variables). Fig.3: this simple LED demonstration program is supplied on the CD-ROM. Fig.4: the CD-ROM includes the source code for the demonstration programs. NE2000-compatible chip has all the hardware “smarts” necessary for network communication and is interfaced to an RJ-45 socket that accepts a standard Cat.5 network cable connector. That means that your RabbitCore module doesn’t even have to be connected directly to your PC in order to talk to it. Instead, it can be anywhere on the local LAN or even “somewhere out there” on the Internet. SMTP email server right into this unit. Think of what you could do with that for industrial process control and monitoring applications. The core module can also be mount­ ed on a user-designed motherboard and can act either as the controlling microprocessor or as a satellite processor to relay network communications. A satellite processor allows remote monitoring of system operation and Web server It’s got other advantages as well. The software CD-ROM included with the core module includes a complete TCP/IP stack (including source code) plus a web server that can be compiled in Dynamic C and downloaded to the Rabbit’s flash memory. Yes, that’s right – you can build an embedded web page server or an 10  Silicon Chip Fig.5: source files for the various network­ing protocols are on the CD-ROM. There are five developer’s kits available for the Rabbit; (1) Rabbit 2000 TCP/IP Developer’s Kit; (2) RabbitCore RCM2000 Developer’s Kit; (3) RabbitCore RCM2100 Developer’s Kit; (4) RabbitCore RCM 2200 Developer’s Kit; and (5) the RabbitCore RCM2300 Development Kit. The developer’s kit pictured in this article is the Rabbit­Core RCM2100. It’s supplied with the following items: (1). The RCM2100 Ethernet core module with 512KB of flash memory and 512KB of static RAM; (2). A prototyping board complete with power supply circuitry, LEDs, switch­ es and prototyping area; (3). An RS232 programming cable (10pin header to DB9); (4). Dynamic C SE CD-ROM – includes royalty-free TCP/IP stack with source plus product documentation; (5). A plugpack power supply; and (6). A “Getting Started Manual”. The “Getting Started Manual” is quite comprehensive and details the hardware setup and the Dynamic C software installa­tion. It also includes several sample Dynamic C programs with full instructions on how to compile and run these, so that you can quickly familiarise yourself with the RabbitCore module. The manual concludes with full circuit diagrams of the RabbitCore RCM­2100 module and the RCM2100 proto­typing board. Catching your Rabbit You can catch your very own silicon Rabbit at Dominion Electronics, Suite 201, 82 Christie St, St Leonards 2065. Phone (02) 9906 6988 or email sales<at> dominion.net.au The RCM 2100 Ethernet Core Module costs $223.00, while the lower-specced RCM2200 retails for $126.00. The development kits, which include the core modules, cost $682 and $580 respectively. The Rabbit 2000 Basic Development Kit is $379.50, while the Rabbit 2000 TCP/ IP Development Kit is $489.50. For more information on what’s in the Rabbit burrow, point your browser SC to www.dominion.net.au www.siliconchip.com.au