Address Multiplexing

Signals A[0] – A[12] and BA[0] – BA[1] on each RAM SO-DIMM make up a 15-bit multiplexed address bus that can support several different types of SDRAM devices. Table 4-2 lists the types of devices that can be used in the iBook by size, configuration, and sizes of row, column, and bank addresses.

Important

The iBook computer supports only the types of SDRAM devices specified in Table 4-2. Other types of DRAM devices should not be used with this computer.


Table 4-2 Types of DRAM devices


Device size Device configuration Row address bits Column address bits
64 Mbits 2 M x 8 x 4 (not recommended) 12 9
64 Mbits 1 M x 16 x 4 12 8
64 Mbits 512 K x 32 x 4 11 8
128 Mbits 4 M x 8 x 4 12 10
128 Mbits 2 M x 16 x 4 12 9
128 Mbits 1 M x 32 x 4 12 8
256 Mbits 8 M x 8 x 4 13 10
256 Mbits 4 M x 16 x 4 13 9



 

© 2002 Apple Computer, Inc. (Last Updated January 3, 2002)