1, the unit of measurement used to measure the size of cyberspace:
Minimum number of computers that can store a 1 or 0
1 the storage space is referred to as 1 or 0 bit (bit)
For convenience, the eight bits are connected, called byte (Byte)
Bytes that we can the smallest unit control program
1KB=1024Byte
1MB=1024KB
2, the type of computer memory
2.1 Register: internal cpu, to be to be used to store operands and results (most expensive), directly connected with the operation member, the operation member is directly read and write operations to register
2.2 cache: usually within cpu, used data buffer (internal cache and the external cache)
2.3, memory: cpu want to put in but the data does not fit the part, external hard drives and other memory storage and exchange, temporary storage, power loss, low price, easy to replace, cpu operating frequency is closer to the operating frequency, but there are still gap.
2.4, external memory:
3, cpu read data
Existing cache lookup, to find immediately read, can not be found, it is read from the memory and to the cpu process with a relatively slow rate, while the data block where the data is transferred to the cache, so that later may be for the entire block data are read from the cache memory does not have to call. (To minimize the possibility of slow reading)
cpu principle of locality:
cpu access to data usually has a certain locality:
Temporal locality: If a memory address is being used, then he is likely to be accessed again in the near future.
Spatial locality: information that may be used is likely to be adjacent to the information currently in use in the near future.
4, what is the principle of memory? Why can store digital live?
Transistor characteristics: a low voltage intermediate, OFF sides; intermediate voltage is high, both sides turned on.
5. What kind of memory? DDR What does it mean?
6. Why can only a 32-bit cpu with 4G memory?
32 is equal to 2 to the power 4G
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