8XC196EA USER’S MANUAL
4.2MEMORY PARTITIONS
Table 4-1 is a memory map of the 8XC196EA. This section describes the partitions.
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Table 4-1. 8XC196EA Memory Map |
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Hex |
Description (Note 1, Note 2) |
Addressing |
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Address |
Modes |
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FFFFFF |
External device (memory or I/O) connected to address/data bus |
Indirect, indexed, |
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FF4000 |
extended |
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FF3FFF |
Program memory (Note 3); can be mapped into page 00H (CCB1.2 = 1) |
Indirect, indexed, |
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FF2400 |
extended |
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FF23FF |
Program memory (Note 3) |
Indirect, indexed, |
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FF2140 |
extended |
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FF213F |
Special-purpose memory (PIH vectors; Note 3) |
Indirect, indexed, |
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FF20C0 |
extended |
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FF20BF |
Program memory (Note 3); |
Indirect, indexed, |
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FF2080 |
(After reset, the first instruction is fetched from FF2080H.) |
extended |
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FF207F |
Special-purpose memory (CCBs, interrupt vectors, PTS vectors); (Note 3) |
Indirect, indexed, |
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FF2000 |
extended |
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FF1FFF |
External device (memory or I/O) connected to address/data bus |
Indirect, indexed, |
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FF1000 |
extended |
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FF0FFF |
Internal code/data RAM (identically mapped from page 00H) |
Indirect, indexed, |
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FF0400 |
extended |
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FF03FF |
Reserved for in-circuit emulators |
— |
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FF0000 |
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FEFFFF |
Overlaid memory (reserved for future microcontrollers); |
Indirect, indexed, |
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1F0000 |
locations xF0000–xF03FFH are reserved for in-circuit emulators |
extended |
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1EFFFF |
External device (memory or I/O) connected to address/data bus |
Indirect, indexed, |
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004000 |
extended |
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003FFF |
A copy of internal ROM (FF2400–FF3FFFH) if CCB1.2=0 |
Indirect, indexed, |
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002400 |
External memory if CCB1.2=1 (Note 4) |
extended |
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0023FF |
External device (memory or I/O) connected to address/data bus |
Indirect, indexed, |
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002000 |
extended |
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001FFF |
Memory-mapped special-function registers (SFRs); (Note 3) |
Indirect, indexed, |
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001FFC |
extended |
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001FFB |
Memory-mapped special-function registers (SFRs) |
Indirect, indexed, |
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001FE0 |
extended |
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001FDF |
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Indirect, indexed, |
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Peripheral special-function registers (SFRs) |
extended, |
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001C00 |
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windowed direct |
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001BFF |
External device (memory or I/O) connected to address/data bus |
Indirect, indexed, |
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001000 |
extended |
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NOTES:
1.Unless otherwise noted, write 0FFH to reserved memory locations and write 0 to reserved SFR bits.
2.The contents or functions of reserved locations may change in future microcontroller revisions, in which case a program that relies on one or more of these locations might not function properly.
3.External memory if EA# is low; internal ROM if EA# is high. (Only applies to the 83C196EA.)
4.When EA# is low, CCB1.2 is ignored. When EA# is high, CCB1.2 controls whether the upper 7-Kbyte section of ROM is mapped into page FFH only or into both pages FFH and 00H. (Only applies to the 83C196EA.)
4-4
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MEMORY PARTITIONS |
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Table 4-1. 8XC196EA Memory Map (Continued) |
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Hex |
Description (Note 1, Note 2) |
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Addressing |
Address |
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Modes |
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000FFF |
Internal code/data RAM (identically mapped into page FFH) |
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Indirect, indexed, |
000400 |
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extended |
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0003FF |
Upper register file (general-purpose register RAM) |
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Indirect, indexed, |
000100 |
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windowed direct |
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0000FF |
Lower register file (general-purpose register RAM) |
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Direct, indirect, |
00001A |
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indexed |
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000019 |
Lower register file (stack pointer and CPU SFRs) |
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Direct, indirect, |
000000 |
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indexed |
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NOTES:
1.Unless otherwise noted, write 0FFH to reserved memory locations and write 0 to reserved SFR bits.
2.The contents or functions of reserved locations may change in future microcontroller revisions, in which case a program that relies on one or more of these locations might not function properly.
3.External memory if EA# is low; internal ROM if EA# is high. (Only applies to the 83C196EA.)
4.When EA# is low, CCB1.2 is ignored. When EA# is high, CCB1.2 controls whether the upper 7-Kbyte section of ROM is mapped into page FFH only or into both pages FFH and 00H. (Only applies to the 83C196EA.)
4.2.1External Memory
Several partitions in pages 00H and FFH and all of pages 01H–1EH are assigned to external memory (see Table 4-1). Data can be stored in any part of this memory. Instructions can be stored in any part of this memory in 2-Mbyte mode, but can be stored only in page FFH in 64-Kbyte mode. Chapter 15, “Interfacing with External Memory,” describes the external memory interface and shows examples of external memory configurations.
4-5