Advantech PCA-6184, User Manual

Page: 20 / 116

PCA-6184, ed. 1 User’s Manual 12
1.8 System Memory
The PCA-6184 contains two sockets for 184-pin dual memory modules
(DIMMs). All these sockets accept only 3.3 V DDR200/DDR266
SDRAM. DIMMs are available in capacities of 64,128, 256, 512 MB and
1 GB. The sockets can be filled in any combination with DIMMs of any
size, giving your PCA-6184 single board computer up to 2 GB of mem-
ory.
1.8.1 Supplementary information about DIMMs
Your PCA-6184 can accept only DDR memory modules with or without
parity. Also note:
• Chips with 9 chips/side support ECC; chips with 8 chips/side do not
support ECC.
1.9 Memory Installation Procedures
To install DIMMs, first make sure the two handles of the DIMM socket
are in the "open" position. i.e. The handles lean outward. Slowly slide the
DIMM module along the plastic guides on both ends of the socket. Then
press the DIMM module right down into the socket, until you hear a
click. This is when the two handles have automatically locked the mem-
ory module into the correct position of the DIMM socket. To remove the
memory module, just push both handles outward, and the memory mod-
ule will be ejected by the mechanism in the socket.
1.10 Cache Memory
Since the second level (L2) cache has been embedded into the Pentium®
4/Celeron™ processor, you do not have to take care of either SRAM
chips or SRAM modules. The built-in second level cache in the Pen-
tium® 4 processor yields much higher performance than the external
cache memories. The cache size in the Pentium® 4 processor is 256/512
KB, depending on the type of CPU. The cache size in Celeron(TM) pro-
cessor is 128KB.
Table 1.5:
DIMM memory capacity sample calculation
Socket number 184-pin DIMM memory
1 64, 128, 256 or 512 MB or 1 GB
2 64, 128, 256 or 512 MB or 1 GB