Tag: Registers
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Data Registers
Data registers are used in microcomputers to hold data temporarily. Normally this data can be accessed faster than if it were to be fetched from the memory. The figure below shows a 4-bit data register that utilizes a negative edge-triggered D flip-flops to transfer data from four data lines to the outputs of four AND…
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How Special Function Registers (SFRs) are Mapped into Memory Space
There are two basic primary architectures used for mapping special function registers into memory space. In the first type of arrangement, I/O space and memory space are separated as illustrated in Figure 1.0. The I/O devices have a separate address space, which is accomplished by either an extra I/O pin on the CPU physical interface…
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CPU Registers
A register is basically an n-bit binary storage element. CPU registers are usually used to temporarily hold data and memory address values that might be required in the near future. Since registers are located within the CPU, they can be accessed more quickly and more efficiently than external memory. Furthermore, since the number of registers…