SOLTEK SL-75DRV3/75DRV3+ User Manual page 126

75DRV3/75DRV3+
SDRAM (Synchronous DRAM)
SDRAM is one of the Dynamic Random Access Memory (DRAM)
technologies that allow DRAM to use the same clock as the CPU host
clock (EDO and FPM are asynchronous and do not have clock signal).
SDRAM comes in 64-bit 168-pin DIMM and operates at 3.3V.
SIMM (Single In Line Memory Module)
SIMM socket is only 72-pin, and is only single side. The golden finger
signals on each side of PCB are identical. That is why it is called Single
In Line. SIMM is made of FPM or EDO DRAM and supports 32-bit
data. SIMM is phased out in current mainboard design.
SPD (Serial Presence Detect)
SPD is a small ROM or EEPROM device resided on the DIMM or RIMM.
Memory module information such as DRAM timing and chip parameters
can be stored into SPD so that BIOS can access it and use it to decide
best timing for this DIMM or RIMM.
UART (Universal Asynchronous Receiver/transmitter)
UART is built in a chip that controls the data sent to and received from
a serial port. A 16550 UART is now standard in most PCs, and supports
modem speed up to 57,600 bps and beyond and direct connect speed of
115,200 bps. Many UARTs have built-in errors in the internal code and
just do not work correctly with many external modems. UART is also
found as the serial interface on internal modem.
Ultra DMA
Ultra DMA (or, more accurately, Ultra DMA/33) is a protocol for
transferring data at 33.3MB/s between a hard disk drive through the
computer's data path (or bus) to the computer's random access memory
(RAM). The transfer data is twice as fast as the previous Direct Access
Memory (DMA) interface. The latest Ultra DMA has advanced to Ultra
DMA/66 and Ultra DMA/100.
16.6MB/s x2 = 33MB/s
16.6MB/s x4 = 66MB/s
16.6MB/s x6 = 100MB/s
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