UPD784044 Datasheet, PDF (18/90 Pages) NEC – 16-BIT SINGLE-CHIP MICROCONTROLLER

µPD784044(A), 784046(A)
6. CPU ARCHITECTURE
6.1 Memory Space
A 1M-byte memory space can be accessed. The mapping of the internal data area (special function registers
and internal RAM) can be selected by using the LOCATION instruction. The LOCATION instruction must be
always executed after the reset signal has been deasserted, and must not be used more than once.
(1) When LOCATION 0 instruction is executed
• Internal memory
The internal data area and internal ROM area are as follows:
Product Name
µPD784044(A)
µPD784046(A)
Internal Data Area
0FB00H-0FFFFH
0F700H-0FFFFH
Internal ROM Area
00000H-07FFFH
00000H-0F5FFH
Caution 0F600H to 0FFFFH of the on-chip ROM (00000H to 0FFFFH) of the µPD784046(A) cannot
be used as ROM in execution of the LOCATION 0 instruction (refer to Figure 6-2).
• External memory
The external memory is accessed in the external memory expansion mode.
(2) When LOCATION 0FH instruction is executed
• Internal memory
The internal data area and internal ROM area are as follows:
Product Name
µPD784044(A)
µPD784046(A)
Internal Data Area
FFB00H-FFFFFH
FF700H-FFFFFH
Internal ROM Area
00000H-07FFFH
00000H-0FFFFH
• External memory
The external memory is accessed in the external memory expansion mode.
18