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 4-7 lists the types of devices that can be used in the PowerBook computer by size, configuration, and sizes of row, column, and bank addresses.

IMPORTANT

The PowerBook computer supports only the types of SDRAM devices specified in Table 4-7. Other types of devices should not be used with this computer.

Table 4-7 Types of DRAM devices

Device size	Device configuration	Row address bits	Column address bits
64 Mbits	2 M x 8 x 4	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