NEC PD17062 - Manual (Page 29)

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PD17062
5. DATA MEMORY (RAM)
Data memory is used to store data for operations and control. Simply by executing an appropriate
instruction, data can be written to and read from data memory at any time.
5.1 STRUCTURE OF DATA MEMORY
Fig. 5-1 shows the structure of data memory.
As shown in Fig. 5-1, data memory is divided into three units called banks. These three banks are called
BANK0, BANK1, and BANK2.
In each bank, data is assigned an address in units of four bits. The high-order three bits are called the row
address, while the low-order four bits are called the column address. For example, the data memory location
having row address 1H and column address AH is referred to as the data memory location having address
1AH. One address consists of four bits of memory. These four bits are called a nibble.
Data memory is divided into the blocks described in Sections 5.1.1 to 5.1.5, according to function.