Bit extension and word extension

1. Bit expansion: This expansion is required when the number of memory chip units used meets the requirements, but the number of bits per unit is low. For example, using 4164 (64k*1) to expand a 64KB storage system requires bit expansion.

The connection diagram is as follows:

The figure shows a storage system that connects the two-chip 64k*4 chip into a 64k*8. The use of bit expansion, the connection points are: Two chip address lines are connected together (that is, A0 and A0 and connect, A1 and A1 and connect, A15 and A15 and so on), to the system address bus; Two the data lines of the chip each provide a portion of the data bus (this example is a high 4-bit and low 4-bit), together constitute

　　

　　

2. Word augmentation: This expansion is required when the number of memory chip bits used meets the requirements, but the number of units is small. For example, using 6264 (8k*8) to expand a 64KB storage system requires word augmentation.

The connection diagram is as follows:

The figure shows a storage system that connects the two-chip 32k*8 chip into a 64k*8. Using Word expansion, its connection points are: two chip low-level address line and connected to the low level of the system address bus, two chip data lines are connected together, connected to the system bus, the system high-level address line, decoding, decoding the output of the two chip is connected to the selected side CS1,CS2.