1 special areas, Special areas – FUJITSU Semiconductor Controller MB89950/950A User Manual

Page 38

Advertising
background image

24

CHAPTER 3 CPU

3.1.1

Special Areas

In addition to the I/O area, the special purpose areas in the memory space include the
general-purpose register area and the vector table area.

General-purpose register areas (addresses: 0100

H

to 01FF

H

)

Provides auxiliary registers for 8-bit arithmetic operation and transfer instructions.

Allocated to a region of the RAM area. Can also be used as normal RAM.

Using the area as general-purpose registers enables high-speed access by general-purpose register

addressing using short instructions.

Table 3.1-1 "General-purpose register areas" lists the areas in each device that can be used for general-

purpose registers.

See section 3.2.2 "Register Bank Pointer (RP)" and section 3.3 "General-purpose Registers" for details.

Table 3.1-1 General-purpose register areas

Part number

MB89951A

MB89953A

MB89P955/PV950

Number of banks

8

16

32

Address range

0100

H

to 013F

H

0100

H

to 017F

H

0100

H

to 01FF

H

Advertising