NEC PD17062 - Manual (Page 18)

18
µ
PD17062
2. PROGRAM MEMORY (ROM)
Program memory stores the program to be executed by the CPU, as well as predetermined constant data.
2.1 CONFIGURATION OF PROGRAM MEMORY
Fig. 2-1 shows the configuration of program memory.
As shown in Fig. 2-1, the capacity of the program memory is 8K bytes (3968
×
16 bits).
Locations in program memory are addressed in units of 16 bits. The total address range is from 0000H
to 0F7FH. Memory is divided into pages. The range of page 0 is from 0000H to 07FFH, while that of page
1 is from 0800H to 0F7FH.
The range from 0800H to 0F7FH can be used as the CROM (character ROM) area in which the display patterns
for the IDC are stored. If this area is not used as CROM, it can be used as a program area.
The range from 0000H to 00FFH is a table reference area. The area is used by the JMP @AR, CALL @AR,
MOVT, PUSH, and POP instructions.
Fig. 2-1 Configuration of Program Memory
Address
Program memory (ROM)
16 bits
Page 0
Page 1 (area that can be used as CROM)
3968 steps
0 0 0 0 H
0 7 F F H
0 8 0 0 H
0 F 7 F H
b
15
b
14
b
13
b
12
b
11
b
10
b
9
b
8
b
7
b
6
b
5
b
4
b
3
b
2
b
1
b
0