UPD784907 Datasheet, PDF (22/98 Pages) NEC – 16-BIT SINGLE-CHIP MICROCONTROLLER

µPD784907, 784908
7. CPU ARCHITECTURE
7.1 Memory Space
A memory space of 1 Mbyte can be accessed. By using a LOCATION instruction, the mode for mapping internal
data areas (special function registers and internal RAM) can be selected. A LOCATION instruction must always be
executed after a reset, and can be used only once.
(1) When the LOCATION 0 instruction is executed
• Internal memory
The internal data area and internal ROM area are mapped as follows:
Part Number
Internal Data Area Internal ROM Area
µPD784907
0F100H to 0FFFFH 00000H to 0F0FFH
10000H to 17FFFH
µPD784908
0EE00H to 0FFFFH 00000H to 0FDFFH
10000H to 1FFFFH
Caution
The following internal ROM areas, existing at the same addresses as the internal data areas,
cannot be used when the LOCATION 0 instruction is executed:
Part Number
Unusable Area
µPD784907
0F100H to 0FFFFH (3,840 bytes)
µPD784908
0EE00H to 0FFFFH (4,608 bytes)
• External memory
The external memory is accessed in external memory expansion mode.
(2) When the LOCATION 0FH instruction is executed
• Internal memory
The internal data area and internal ROM area are mapped as follows:
Part Number
Internal Data Area Internal ROM Area
µPD784907
FF100H to FFFFFH 00000H to 17FFFH
µPD784908
FEE00H to FFFFFH 00000H to 1FFFFH
• External memory
The external memory is accessed in external memory expansion mode.
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Data Sheet U11680EJ2V0DS00