NEC 78K/0 Series - Manual (Page 13)

13
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 IEBus TM 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.