Filter
Top Products
Chapter 3 Hardware
22 Reference Manual LittleBoard 550
CPU (U1)
The LittleBoard 550 offers three VIA Technologies Eden processor choices; high performance 1GHz
ESP 10000 processor, 533MHz ESP 5000 processor, or the low cost, 300MHz ESP3000 processor.
ESP Processors
The ESP (0.13µ or 0.15µ) processors at 1GHz, 533MHz, or 300MHz use 133MHz, 133MHz, or 66MHz
FSB (front side bus) respectively, with 128kB Level 1 cache and 64kB Level 2 cache. The ESP
processors require a heatsink, but no fan.
NOTE A CPU fan connector is provided for your convenience to
accommodate any special requirements. See Table 3-28.
Memory
The LittleBoard 550 memory consists of the following elements:
• SDRAM
• Flash memory
• Serial EEPROM (SEEP)
SDRAM Memory (DIMM1)
The LittleBoard 550 supports a single standard 168-pin DIMM slot.
• DIMM slot can support up to 2GB of memory
• Supports PC 133 (133MHz, 7.5ns) and PC 100 (100MHz, 10ns)
• +3.3V SDRAM
NOTE Ampro recommends using only PC 133 (133MHz), 3.3V, 7.5ns, 168-
pin, SDRAM DIMM, but PC 100 (100MHz, 10ns) will function. PC
133 provides the best performance for the Eden processors.
Flash Memory (U17)
There is an 8-bit wide, 512kB flash device used for system BIOS that is connected to the Southbridge,
VT82C686B, through an ISA bus transceiver. The BIOS is re-programmable and the supported features
are detailed in Chapter 4, BIOS Setup.
Serial EEPROM (SEEP)
The 2-wire Serial EEPROM (SEEP) contains 4k-bits and at least 512-bit area is reserved for the user.
The SEEP is used to store system parameters for battery-free boot capability when there is no battery
present. The SEEP uses the SMBus as its 2-wire interface.