Main Ram Circuit - Panasonic JS-170FR Series Service Manual

2.1.3

Main RAM circuit

A 3.3V DIMM (168-pin) is used for the main RAM of this system.
The DIMM can mount an SDRAM or EDO type memory and the installed capacity is controlled by the software. The circuit
provided with the ECC parity is also available.
The maximum capacity of a single DIMM is 128Mbytes. Therefore, it is possible to increase the capacity up to 256Mbytes if two
chips are used.
Both SDRAM and EDO can be mounted in mixture. There is no discrimination in mounting positions.
For the EDO, refreshment is controlled by the FW82443BX. At every period of about 15µsec., refreshment is carried out by the
CAS before RAS system.
The speed used for the EDO is 60nsec. max., and 10nsec. max. for the SDRAM.
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