UPD77018A NEC, UPD77018A Datasheet - Page 20

• Manufacturer Part Number: UPD77018A
• Description: 16 bits/ Fixed-point Digital Signal Processor
• Manufacturer: NEC

20
2.4.1 Instruction RAM Outline
and rewritten by boot program.
The PD77018A has an instruction ROM (24K words
The PD77019 has an instruction ROM (24K words
A system vector area is assigned to 64 words of the instruction RAM. Internal instruction RAM is initialized
Boot up ROM contains the program loading instruction code to internal instruction RAM.
Caution
When any data is accessed or stored to system address, normal operation of the device is
not assured.
FFFFH
A000H
9FFFH
3FFFH
02FFH
023FH
01FFH
00FFH
4000H
0300H
0240H
0200H
0100H
0000H
Bootup ROM (256 words)
Internal Instruction ROM
System (15.25K words)
Internal Instruction RAM
System (24K words)
System (256 words)
Vector (64 words)
PD77018A
(24K words)
(256 words)
32 bits) and instruction RAM (4K words
32 bits) and instruction RAM (256 words
11FFH
1200H
Internal Instruction ROM
Bootup ROM (256 words)
Internal Instruction RAM
System (11.5K words)
System (24K words)
System (256 words)
Vector (64 words)
(24K words)
PD77019
(4K words)
PD77018A, 77019
32 bits).
32 bits).