78K datasheet(13/129 Pages) NEC

13 / 129 page

CHAPTER 1 MEMORY SPACE

User's Manual U12326EJ4V0UM

(3) RAM for VFD display

There are some products in the 78K/0 Series to which RAM for VFD display is allocated. This RAM can

also be used as an ordinary RAM area.

(4) Internal expansion RAM

There are some products in the 78K/0 Series to which internal expansion RAM is allocated.

(5) RAM for LCD display

There are some products in the 78K/0 Series to which RAM for LCD display is allocated. This RAM can

also be used as an ordinary RAM area.

1.7 Special Function Register (SFR) Area

On-chip peripheral hardware special function registers (SFRs) are allocated in the area FF00H to FFFFH (for

details of the special function registers, refer to the user’s manual of each product).

Caution Do not access addresses to which SFRs are not allocated. If an address is erroneously

accessed, the CPU may become deadlocked.

1.8 External Memory Space

This is an external memory space that can be accessed by setting the memory extension mode register. This

space can store program and table data, and be assigned peripheral devices.

For details of the products in which an external memory space can be used, refer to the user’s manual of each

product.

1.9 IEBusTM Register Area

IEBus registers that are used to control the IEBus controller are allocated to the IEBus register area.

For details of the products that incorporate an IEBus controller, refer to the user’s manual of each product.

78K Folha de dados(PDF) 13 Page - NEC