The Pentium CPU has its standard on-chip cache memory (typically 16K). In addition, a 512K byte synchronous-burst secondary cache is provided to increase performance.
The board uses a single DIMM memory module for main DRAM memory, and supports from 16M bytes to 256M bytes in a 64-bit configuration. Both EDO and SDRAM 3.3V DRAM types are supported. (5V DRAMS, ECC, and DRAM parity are not supported.)
The module has a full complement of standard PCI PC/AT architectural features, including DMA channels, interrupt controllers, real-time clock, and timer counters.
Enhanced Embedded-PC BIOS
One of the most valuable features of the Little Board/P5x is its enhanced embedded-PC BIOS, which includes an extensive set of functions that meet the unique requirements of embedded- system applications. These enhancements include:
!Compact Flash support. You can use a solid-state Compact Flash memory module in place of a rotating media drive (see Compact Flash Disk, below).
!Watchdog timer. The WDT monitors the boot process and can be integrated into application programs using function calls provided in the BIOS.
!Fast boot operation. Normal or accelerated POST.
!Fail-safe boot support. Intelligently retries boot devices (configured in the BIOS) until a successful boot.
!Battery-free boot support. Saves system Setup information in non-volatile EEPROM. The board can use this information should the RTC battery fail.
!Serial console option. Lets you use a serial device, such as an ASCII serial terminal, as console.
!Serial loader option. Supports loading boot code from an external serial source.
!EEPROM access function. 256 bits of serial EEPROM storage are available to the user, useful for serialization, copy protection, security, etc.
!OEM customization hooks. The module can execute custom code prior to system boot via ROM extensions; allows sophisticated system customization without BIOS modification
Modular PC/104-PlusExpansion Bus
The Little Board/P5x provides a PC/104-Plusexpansion bus for additional system functions. This bus offers compact, self-stacking, modular expandability. The PC/104-Plusexpansion bus is an extension of the PC/104 bus. The PC/104 bus is defined in the IEEE P996.1 Standard for Compact Embedded PC Modules. It is an embedded system version of the signal set provided on a desktop PC's ISA bus. The PC/104-Plusbus includes this signal set, and in addition, signals implementing a PCI bus, available on an additional 120-pin PCI bus connector.
The growing list of PC/104 and PC/104-Plus modules available from Ampro and hundreds of other PC/104 vendors includes such functions as communications interfaces, video frame grabbers, field bus interfaces, digital signal processors (DSPs), data acquisition and control functions, and many specialized interfaces and controllers. In addition, custom application-specific logic boards can also