Address line and bus
Each byte (byte) in the DRAM assigns a unique digital identifier called "address". An address is an integer value. The first byte allocated in memory is zero. Near The memory area of zero addresses is often referred to as "Bottom of Memory or Low Memory". The memory space physical byte indicates the physical address space of the processor addressable.
The physical address space of the processor determines the number of address buss it has. The address bus is a metal line connected to the DRAM chip, each address line specifies a bit in a Given Byte (a Single The address of Bit) (Each Address Line Specifies A Given Byte.), for example, Intel Pentium has 32 address lines, which means that each byte is assigned a 32-bit (BIT) address, So its accepted space consists of 232 sets of address bytes (4GB).
NOTE If virtual memory is enabled on the Pentium 4, there is a way to enable four additional address lines using what is known as Physical Address Extension (PAE). This allows the Pentium processor's physical address space to be defined by 36 address lines, which Translates Into An Address Space of 236 Bytes (64GB).
The processor uses a control bus and a data bus to access and update physical memory. Bus BUS is a metal wire connected to the hardware subsystem. The control bus is used to indicate whether the processor reads from memory, or writes in memory The data bus is used to transport data between processors and memory. When the processor reads memory, the following steps are performed:
1. Processor will need to read and add the address of the address to the address bus
2. The processor sends a read signal to the control bus.
3. DRAM chip returns the byte specified on the data bus.
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When the processor writes memory, the following steps are performed:
1. The processor will be written to the address bus.
2. The processor sends a write signal to the control bus.
3. The processor sends the byte to be written to the data bus.
It is somewhat excessive purification. For example, the Pentium Processor Reads and Writes Data 4 Bytes At A Time. This is One Reason Why The Pentium Is Called A 32-Bit Chip. The Processor Will Refer To ITS 32-Bit PayLoad Using The Address of The First Byte (IE, The Byte with The Lowest Addest). Nevertheless, I Think The General Operation Is Clear.
