R38 0EX

The RadiSys R380EX Embedded System Controller is a member of the RadiSys family of embedded core logic specifically designed to support the Intel386EX processor. Providing the necessary circuitry for a PC-compatible embedded system design, it supplies a simple, low-cost, "glueless" interface to additional chips like a video controller or a PCMCIA controller.

The functional design of the R380EX is directly derived from PC architecture. The R380EX includes a DRAM controller, keyboard/mouse controller, real time clock, enhanced IDE interface, and ISAbus controller.

The DRAM controller is compatible with both fast-page-mode (FPM) and extended-data-out (EDO) DRAM. The R380EX can be configured to support both DRAM SIMMs and flash SIMMs for greater system flexibility. The enhanced IDE interface supports a maximum transfer rate of 8.33MB per second. The ISAbus controller has a separate data bus, and manages the ISA signals to ensure a "quiet" bus for cycles not directed to the ISA address space.

The power management capabilities of the R380EX include clock source switching, halt detection, SMI event generation, and a programmable clock restart delay to ensure clock frequency settling when restarting the oscillator from a powerdown state. The clock source for the Intel386EX processor can be switched between the R380EX CLK2OSC input and the 32.768KHz real time clock oscillator, thereby reducing the system power consumption.

The R380EX has 4 user-programmable I/O chip selects in addition to the Intel386EX processor's chip selects. There are 16 bits of individually programmable digital I/O along with 6 bits of digital output. Additional functional blocks handle the Intel386EX processor halt and shutdown cycles, and control the speaker and external LEDs. The main and alternate functions of many of the pins are controlled through registers within the R380EX.