The V104 from TERN is a low cost, high performance, C/C++ programmable 16-bit microcontroller. By building your product around the V104, you reduce the time from design to market introduction, cut development costs, minimize technical risks, and deliver a more reliable product. Measuring 3.5 x 4.0 x 0.5 inches, the V104 features 24 I/O (multiplexed functions) lines from the V25 CPU, eight comparator inputs, three 16-bit timers, two external event counters, up to three serial ports, three external interrupts, and 24 additional bi-directional I/O lines from the PPI 82C55. Other features available include 11 channels of 12-bit ADC inputs, 4 channels of 12-bit DAC outputs, up to 512K of battery backed-up SRAM, up to of 512K EPROM or Flash EEPROM, 512 byte EEPROM, LCD interface, real time clock, LED, and a supervisor chip providing power failure detection, watchdog timer, and reset.

Three serial ports are supported: V25-internal SER0 and SER1, and an optional UART (SCC2691) that supports 8-bit or 9-bit communication. The V25-internal 24 I/O lines are multifunctional and can be programmed as control, input, or output. Three 16-bit timers can provide precise timing for applications.

The V104 is so designated because of its provision of a PC/104 bus, which is a 64 pin connector with standard 8-bit PC ISA bus signals. The V104 can map the conventional PC BIOS memory space and I/O space to its PC/104 bus. The V104 is not designed with the PC/104 form factor (3.6 x 3.8) for stacking many PC/104 modules. The V104 supports only one or two PC/104 peripheral boards.

The eight comparator inputs can be used to measure either digital or analog inputs. Three external interrupt inputs can trigger the immediately execution of user interrupt service routes. Two counters can count input pulse rising edges up to 500KHz.

The 12-bit ADC has a serial interface, successive-approximation, and sample-and-hold. The ADC features differential high-impedance reference inputs that facilitate ratiometric conversion, scaling, and isolation of analog circuitry from logic and supply noise, with low-error (*1LSB) over the full operating temperature range at 2500 Hz sample rate. It also features high-impedance reference inputs. The ADC input voltage range is 0V to 2.5V or 0V to 5V depending on reference voltage.

The 4 channel 12-bit DAC voltage outputs (0V to 2.5V) are internally buffered by precision unity-gain followers with a typical slew rate of 3V/us with 5Kohm load. The V104 must be powered by a regulated 5V. The DAC also requires an external -5V power supply.

A 16-pin header LCD interface supports 16x2 character LCD, as well as a number of other TERN LCDs.

The V104 expects a regulated +-5V voltage supply, and does not provide RS232 drivers for the serial ports. The VE232 can be used to provide this. The V104 can also be installed on the A-Drive, which also provides an additional 11 channels of 12-bit ADC along with a voltage sup