Datasheet

Microcomputer/controller
with Embedded BASIC Interpreter

FEATURES

• Small size: complete computer/controller with I/O in less than 1.5 in.³ (1.5" x 2.1" x 0.5")
• Low power: only 100 mW typical
• Dual powered: operates on +5 V or 8 - 16 V at 15 mA (typical)
• Communications through RS-232A, RS-422, or RS-485 serial port up to 19.2 kbps; internal on-chip level shifters
• Full floating-point BASIC for easy programming
• Two firmware PWM outputs: 2 Hz - 3 kHz, 5 - 95% duty cycle
• Hardware PWM output: up to 1 MHz, depending on duty cycle
• Frequency measurement: 15 Hz - 15 kHz
• I²C bus
• 32-KB SRAM for "enter and execute" program testing
• 32-KB EEPROM nonvolatile storage for autostart applications
• Hardware real-time clock/calendar
• 40-pin DIP-style enclosed packaging with rugged square pins
• Optional 2-channel, 12-bit ADC, 10k samples/second
• 11.059-MHz system clock
• 2 interrupts and 3 timers
• Parallel I/O: 12 bits of bit-programmable TTL-level and 16 bits of bit-programmable high current drive I/O lines; 25-mA sink per pin with 20-mA source per pin
• Regulated 5-V output powers external circuitry

DESCRIPTION

The Domino2 microcontroller is a rugged, miniature controller with a fast, control-oriented, processor-masked BASIC interpreter. Domino2 programs can be entirely BASIC or a mixture of BASIC and assembly-language routines with a BASIC CALL instruction.

Domino2 is designed to be a 100% stand-alone, low-power, embedded controller which only requires a user to apply power to function. Power can be either +5 V only or +8 - 16 V to the internal regulator. When using the regulator input, a 5-V output is available to external circuitry.

Domino2 is both RS-232A and RS-485 compatible without extra components. Based on a CMOS 80C52 processor, Domino2 provides a ROM-resident BASIC interpreter, 32 KB of static RAM, and 32 KB of nonvolatile EEPROM.

Domino2 has 12 bidirectional bit-programmable parallel I/O lines (3 are shared with the ADC) plus 16 bits of bidirectional, bit-programmable high-current I/O lines provided by a built-in I²C parallel expander. These bits can source/sink more than 20 mA each (limited by total package dissipation). The coprocessor also offers a hardware PWM output and a real-time clock/calendar. Analog input is via a 2-channel sample-and-hold 12-bit ADC. It is capable of sampling at 10k samples per second.

Additional firmware enables program calls to directly read frequency and period, set PWM pulse width and duty cycle, communicate with I²C bus peripherals, and save programs to EEPROM that can be autostarted.

Domino2 combines the ROM-resident BASIC with a selection of firmware program calls to directly read frequency and period, set PWM pulse width and duty cycle, communicate with I²C bus peripherals, and save programs to EEPROM that can be autostarted.

PIN DESCRIPTION

MECHANICAL AND ENVIRONMENTAL CHARACTERISTICS

Length: 2.25 inches
Width: 1.375 inches
Height: 0.52 inches
Weight: 25 grams
Operating temperature: 0 to +70°C (optional -40 to + 85°C)
Humidity: 0 to 100% (noncondensing)

ABSOLUTE MAXIMUM RATINGS

Operating temperature: 0 to +70°C commercial (optional -40 to + 85 °C industrial)
Storage temperature -50°C to +125°C
Voltage on V+ (Pin 1): 0 to +16 V, referenced to Vss
Voltage on +5V (Pin 40): 0 to +5.5 V, referenced to Vss with Pin 1 open
Voltage on Vbat (Pin 2) 0 to +5.0 V
Industrial temperature version is available; minimum quantities apply.

PROGRAMMING CHARACTERISTICS

Domino2 is a complete computer/controller in one tiny package. The embedded BASIC interpreter and firmware provide the user with a direct means to enter and save an autostarting control program without expensive development tools. Such powerful advantages facilitate completing a programming task in record time. You can write, test, and save code in nonvolatile storage directly on Domino2.

The friendly, control-oriented BASIC command set allows easy access to the integrated digital and analog I/O functions. Conversion calculations are a breeze thanks to BASIC's floating-point number crunching. Because of the power of a high-level language such as BASIC, useful programs often take less than a dozen programming statements. Nonetheless, Domino2 has over 30 KB of space reserved for your application code and the utilities.

Even though Domino2 is optimized for BASIC programs, assembly language programs are easily accommodated as callable routines. A Domino2 application program can be all BASIC, BASIC with callable assembly language routines, or virtually all assembly language with the only BASIC command being an introductory CALL.

Domino2 contains all the communication interface hardware. It can be used standalone to monitor analog and digital inputs and to provide control outputs directly to machine or network interfaces. When connected serially, Domino2 can serve as a remote device, reporting monitored conditions to your PC or receiving commands to control external components. If multiple Domino2s are networked with a master PC or another Domino2, multi-drop units can share information collected throughout the network.

I/O COPROCESSOR

DOMINO-2 is equivalent to the original DOMINO-52/52A plus additional I/O provided by an onboard I/O coprocessor. The I/O coprocessor is connected to the BASIC processor via the I2C bus. It provides 16 bits of high current drive digital I/O, a hardware background PWM, and a RTClock/calendar. The coprocessor can maintain the correct time and date even if main power is removed by connecting an auxiliary battery source to the Vbat input (Pin 2). Each of the 16 digital I/O pins can be individually programmed as either input or output and they have the capability to directly drive LEDs either sinking or sourcing current.

DOMINO-2's coprocessor is physically connected to the BASIC processor's I2C I/O lines (P1.7 and P1.6). These two pins may also be used to add external I2C devices (see section 4.6). With the exception of I2C expansion peripherals, these two lines should not be used for direct I/O. Circuitry connected to these lines may interfere with the coprocessor.

Coprocessor communications are handled as an I2C register write or register read. The coprocessor is defined as address 20H. There are 51 8-bit registers which can be written to or read from. Each has a distinct address and function. They are defined below.

DOMINO2 COPROCESSOR REGISTER DEFINITIONS