Difference between revisions of "Hardware:Memory Map"
From Motorola 68000 Homebrew Computer Project
(Created page with "The 16MB of address space will be broken up into 8 2MB chunks by a 74LS138 3-to-8 decoder. 0MB: 0x00000000 - 0x000FFFFF ROM 1 MB 1MB: 0x00100000 - 0x001FFFFF Reserved 1 MB, po...") |
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Memory mapped I/O area from 0x00200000 - 0x003FFFFF will be broken down with another 74LS138 into 8 256KB chunks or maybe with a 4-to-16 decoder for 16 chunks. | Memory mapped I/O area from 0x00200000 - 0x003FFFFF will be broken down with another 74LS138 into 8 256KB chunks or maybe with a 4-to-16 decoder for 16 chunks. | ||
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| + | Here is my WIP memory decoder showing flash ICs and one SRAM. 74LS138 in lower left will be replaced with a 1-to-2 decoder, I just didn't see one in the component library and didn't feel like adding it. | ||
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| + | [[Image:memdec.png]] | ||
Revision as of 08:55, 9 March 2011
The 16MB of address space will be broken up into 8 2MB chunks by a 74LS138 3-to-8 decoder.
0MB: 0x00000000 - 0x000FFFFF ROM 1 MB 1MB: 0x00100000 - 0x001FFFFF Reserved 1 MB, possible future use for more memory mapped I/O or VRAM, etc. 2MB: 0x00200000 - 0x003FFFFF Memory Mapped I/O 2 MB 4MB: 0x00400000 - 0x00FFFFFF Static RAM 12 MB
Memory mapped I/O area from 0x00200000 - 0x003FFFFF will be broken down with another 74LS138 into 8 256KB chunks or maybe with a 4-to-16 decoder for 16 chunks.
Here is my WIP memory decoder showing flash ICs and one SRAM. 74LS138 in lower left will be replaced with a 1-to-2 decoder, I just didn't see one in the component library and didn't feel like adding it.
