Memory Interfacing

1. if a memory chip is organized in a 4096 x 1 format, specify the number of registers in the chip and the number of bits stored by each register. 2. if 16K x 1 memory chips are used in a memory design, how many chips are required to design 64K-byte memory? 3. Specify the […]
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  To read from memory, the address of the register to be read from should be placed on the address lines; arid the Chip Enable C͞E and R͞D signals must be , asserted low to enable the Output buffer. To write into memory, die address of the register to be written into should be placed […]
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In the above discussion of memory interfacing, we focused on certain aspects of the communication process between the Z80 and memory. However, in order to avoid distraction from basic concepts, we did not address several important is­sues. Now we will attempt to answer those questions briefly or provide references for them : . . How […]
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In the last section, we discussed how to design or interface .memory for a given address. The next step is to test and verify that we can store a byte at a memory location within the address range of the memory chip and read the byte. At this point, we need to make an assumption […]
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In this example, we will use the MOSTEK MK4802 memory chip to demonstrate both Read and Write operations. To simplify the discussion, we will use the same decoding circuit as in Figure 7, except the M͞S͞E͞L4 signal is used as the Chip Enable. This chip has 2K of memory; therefore, two address lines (A12 and […]
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In this section, we will illustrate memory interfacing with the Z80 microprocessor by using an actual chip: the 2764 PROM (Erasable Programmable Read-Only- memory). This is a memory chip commonly used in industry to develop microprocessor-based products .. In this illustration, we will assume that the chip bas been already programmed-that is the binary patterns […]
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In Topic 3, we showed t e timing diagrams and the Z80 bus contents When an opcode or a data byte is fetched from memory. To read from memory, the Z80 performs the following steps, as shown in Figure 2(a) : 1- Places a 16-bit address on its address bus (shown as high- and low […]
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Memory is an integral part of a microprocessor ­based system, and in this topic our focus will be on how to interface a memory chip with the microprocessor. We will examine memory structure and requirements to read from it an write into it, We then compare those require­ments with those of the Z80 Memory Read […]
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