Memory Management - Revision history

WF: /* Numerical address computations for SRAM/VICKY pointers */

2026-02-22T04:56:28Z

Numerical address computations for SRAM/VICKY pointers

← Older revision		Revision as of 00:56, 22 February 2026
Line 230:		Line 230:
	<code>SRAM address = ((MMU Block & 0x300) << 11) \| ((MMU Block & 0x03F) << 13) \| (Byte offset)</code>		<code>SRAM address = ((MMU Block & 0x300) << 11) \| ((MMU Block & 0x03F) << 13) \| (Byte offset)</code>

	<code>MMU Block number = ((SRAM Address & 0x180000) >> 11) \| ((SRAM address & ~~0x07fe000~~) >> 13)</code>		<code>MMU Block number = ((SRAM Address & 0x180000) >> 11) \| ((SRAM address & 0x07e000) >> 13)</code>

	<code>MMU byte offset = SRAM Address & 0x001fff</code>		<code>MMU byte offset = SRAM Address & 0x001fff</code>

WF: /* Memory Block Tables */

2026-02-22T03:58:45Z

Memory Block Tables

← Older revision		Revision as of 23:58, 21 February 2026
Line 590:		Line 590:
	\|-		\|-
	! scope=col \| Block Number		! scope=col \| Block Number
	! scope=col \| SRAM Address		! scope=col \| Flat/SRAM Address

	! scope=col \| Block Number		! scope=col \| Block Number
	! scope=col \| SRAM Address		! scope=col \| Flat/SRAM Address

	! scope=col \| Block Number		! scope=col \| Block Number
	! scope=col \| SRAM Address		! scope=col \| Flat/SRAM Address
	\|-		\|-
	\|$100\|\|$08:0000 - $08:1FFF\|\|$200\|\|$10:0000 - $10:1FFF\|\|$300\|\|$18:0000 - $18:1FFF		\|$100\|\|$08:0000 - $08:1FFF\|\|$200\|\|$10:0000 - $10:1FFF\|\|$300\|\|$18:0000 - $18:1FFF

WF: /* 8kB Block Layout */

2026-02-22T03:57:48Z

8kB Block Layout

← Older revision		Revision as of 23:57, 21 February 2026
Line 178:		Line 178:
	!0		!0
	\|-		\|-
	\|'''MLUT'''		\|'''MLUT Entry'''
	\| colspan="14" \|		\| colspan="14" \|
	\| colspan="10" \|Block Number		\| colspan="10" \|Block Number
	\|-		\|-
	\|'''MLUT'''		\|'''MLUT Entry'''
	\| colspan="14" \|		\| colspan="14" \|
	\| colspan="2" \|<u>''Expansion''</u>		\| colspan="2" \|<u>''Expansion''</u>
Line 192:		Line 192:
	\|'''16-bit MMU Address'''		\|'''16-bit MMU Address'''
	\| colspan="8" \|		\| colspan="8" \|
	\| colspan="3" \|MLUT ~~Entry~~		\| colspan="3" \|MLUT Number
	~~\| colspan="13" \|Byte offset in 8k block~~
	\|-
	~~\|'''16-bit MMU Address'''~~
	~~\| colspan="8" \|~~
	~~\| colspan="3" \|MLUT Entry~~
	\| colspan="13" \|Byte offset in 8k block		\| colspan="13" \|Byte offset in 8k block
	\|-		\|-

WF: /* Flat Memory Models */

2026-02-21T20:27:24Z

Flat Memory Models

← Older revision		Revision as of 16:27, 21 February 2026
Line 58:		Line 58:
	\|64k		\|64k
	\|Core2x: 8×8kB MMU banked		\|Core2x: 8×8kB MMU banked
	F256K2e: SRAM, ~~expect~~ last 256 bytes		F256K2e: SRAM, except last 256 bytes
	\|-		\|-
	\|$00:FF00 - $00:FFFF		\|$00:FF00 - $00:FFFF
Line 89:		Line 89:

	=== 8kB Block Layout ===		=== 8kB Block Layout ===
	The MMU splits the 64kB address space into 8 visible slots of 8kB each. A theoretical max of 256 selectable 8kB blocks yields a 2MB address space, which maps 512kB RAM, flash, and expansion.		The MMU splits the 64kB address space into 8 visible slots of 8kB each. A theoretical max of 256 selectable 8kB blocks yields a 2MB address space, which maps 512kB RAM, flash, and expansion. Devices are laid out every 64 ($40) blocks (512kB).

	The Core2x MMU expands the bank numbers to 10 bits, repeating the original layout 4 times, to expose all 2MB of SRAM while remaining backwards compatible.		The Core2x MMU expands the bank numbers to 10 bits, repeating the original layout 4 times, to expose all 2MB of SRAM while remaining backwards compatible.
Line 178:		Line 178:
	!0		!0
	\|-		\|-
	\|'''~~Block~~'''		\|'''MLUT'''
	\|—		\| colspan="14" \|
	\| colspan="10" \|~~MMU Block Number~~		\| colspan="10" \|Block Number
	\| colspan="13" \|~~Byte offset in 8k block~~
	\|-		\|-
	\|'''~~Block~~'''		\|'''MLUT'''
	\|—		\| colspan="14" \|
	\| colspan="2" \|<u>''Expansion''</u>		\| colspan="2" \|<u>''Expansion''</u>
	\| colspan="2" \|Device		\| colspan="2" \|Device
	\| colspan="6" \|Block ~~number~~ in device (00-3F)		\| colspan="6" \|Block offset in device (00-3F)
			\|-
			\| colspan="25" \|
			\|-
			\|'''16-bit MMU Address'''
			\| colspan="8" \|
			\| colspan="3" \|MLUT Entry
			\| colspan="13" \|Byte offset in 8k block
			\|-
			\|'''16-bit MMU Address'''
			\| colspan="8" \|
			\| colspan="3" \|MLUT Entry
	\| colspan="13" \|Byte offset in 8k block		\| colspan="13" \|Byte offset in 8k block
	\|-		\|-
Line 197:		Line 207:
	\|0		\|0
	\| colspan="2" \|''<u>Expansion</u>''		\| colspan="2" \|''<u>Expansion</u>''
	\| colspan="6" \|Block ~~number~~ in device (00-3F)		\| colspan="6" \|Block offset in device (00-3F)
	\| colspan="13" \|Byte offset in 8k block		\| colspan="13" \|Byte offset in 8k block
	\|-		\|-
Line 206:		Line 216:
	\|1		\|1
	\|1		\|1
	\| colspan="6" \|Block ~~number~~ in device (00-3F)		\| colspan="6" \|Block offset in device (00-3F)
	\| colspan="13" \|Byte offset in 8k block		\| colspan="13" \|Byte offset in 8k block
	\|-		\|-
Line 215:		Line 225:
	\|1		\|1
	\|0		\|0
	\| colspan="6" \|Block ~~number~~ in device (00-3F)		\| colspan="6" \|Block offset in device (00-3F)
	\| colspan="13" \|Byte offset in 8k block		\| colspan="13" \|Byte offset in 8k block
	\|}		\|}
	Device = SRAM, Flash, Cartridge, or Reserved		Device = SRAM (0), Flash (1), Cartridge (2), or Reserved (3)

			===== Numerical address computations for SRAM/VICKY pointers =====
			Full Gen 2 2MB:

			<code>SRAM address = ((MMU Block & 0x300) << 11) \| ((MMU Block & 0x03F) << 13) \| (Byte offset)</code>

			<code>MMU Block number = ((SRAM Address & 0x180000) >> 11) \| ((SRAM address & 0x07fe000) >> 13)</code>

			<code>MMU byte offset = SRAM Address & 0x001fff</code>

			Gen 1, or only using the first 512kB:

			<code>SRAM address = (MMU Block << 13) \| (Byte offset)</code>

			<code>MMU Block number = (SRAM address >> 13)</code>

			<code>MMU byte offset = SRAM Address & 0x001fff</code>

	=== Configuring the MMU ===		=== Configuring the MMU ===

WF: /* Flat Memory Models */

2026-02-21T19:59:37Z

Flat Memory Models

← Older revision		Revision as of 15:59, 21 February 2026
Line 55:		Line 55:
	!Description		!Description
	\|-		\|-
	\|$00:0000 - $00:~~FEFF~~		\|$00:0000 - $00:FFFF
	\|64k ~~- 256~~		\|64k
	\|Core2x: 8×8kB MMU banked		\|Core2x: 8×8kB MMU banked
	F256K2e: SRAM		F256K2e: SRAM, expect last 256 bytes
	\|-		\|-
	\|$00:FF00 - $00:FFFF		\|$00:FF00 - $00:FFFF
	\|256		\|256
	\|Mirror of the last page of Flash, for boot purposes		\|F256K2e only: Mirror of the last page of Flash, for boot purposes
	\|-		\|-
	\|$01:0000 - $1F:FFFF		\|$01:0000 - $1F:FFFF

WF: /* Memory Block Tables */

2026-02-21T19:41:03Z

Memory Block Tables

← Older revision		Revision as of 15:41, 21 February 2026
Line 422:		Line 422:
	\|-		\|-
	! scope="col" \| Block Number		! scope="col" \| Block Number
	! scope="col" \| Flat Address		! scope="col" \| Flat/SRAM Address

	! scope="col" \| Block Number		! scope="col" \| Block Number
Line 568:		Line 568:
	\|-		\|-
	! scope=col \| Block Number		! scope=col \| Block Number
	! scope=col \| ~~Flat~~ Address		! scope=col \| SRAM Address

	! scope=col \| Block Number		! scope=col \| Block Number
	! scope=col \| ~~Flat~~ Address		! scope=col \| SRAM Address

	! scope=col \| Block Number		! scope=col \| Block Number
	! scope=col \| ~~Flat~~ Address		! scope=col \| SRAM Address
	\|-		\|-
	\|$100\|\|$08:0000 - $08:1FFF\|\|$200\|\|$10:0000 - $10:1FFF\|\|$300\|\|$18:0000 - $18:1FFF		\|$100\|\|$08:0000 - $08:1FFF\|\|$200\|\|$10:0000 - $10:1FFF\|\|$300\|\|$18:0000 - $18:1FFF

WF: /* 8kB Block Layout */ fixed block to flat construction table

2026-02-21T18:06:07Z

8kB Block Layout: fixed block to flat construction table

@@ Line 151: / Line 151: @@
 {| class="wikitable"
-|+Final MMU Address Construction
+|+MMU Block Address Construction
-!<u>''22''</u>
-!<u>''21''</u>
+!23
 !20
 !19
@@ Line 176: / Line 178: @@
 !0
 |-
 | colspan="10" |MMU Block Number
-| colspan="13" rowspan="2" |Byte offset in 8k block
+| colspan="13" |Byte offset in 8k block
 |-
 | colspan="2" |<u>''Expansion''</u>
 | colspan="2" |Device
-| colspan="6" |Block number in device
+| colspan="6" |Block number in device (00-3F)
 |}
 Device = SRAM, Flash, Cartridge, or Reserved

WF: /* 8kB Block Layout */ Fixed block to flat mapping

2026-02-21T17:43:23Z

8kB Block Layout: Fixed block to flat mapping

← Older revision		Revision as of 13:43, 21 February 2026
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	!MMU 8kB Block Number!!Purpose		!MMU 8kB Block Number!!Purpose
	!Flat memory flag		!Flat memory flag
			!Flat address
	\|-		\|-
	\|$00 - $3F\|\|512K SRAM <u>''(Page 0)''</u>		\|$00 - $3F\|\|512K SRAM <u>''(Page 0)''</u>
	\|		\|
			\|$00:0000 - $07:FFFF
	\|-		\|-
	\|$40 - $7F\|\|512K System Flash		\|$40 - $7F\|\|512K System Flash
	\|<u>''MOVE_FLASH''</u>		\|<u>''MOVE_FLASH''</u>
			\|$F8:0000 - $FF:FFFF
	\|-		\|-
	\|$80 - $9F\|\|256K Cartridge		\|$80 - $9F\|\|256K Cartridge
	\|<u>''MOVE_FLASH''</u>		\|<u>''MOVE_FLASH''</u>
			\|$F4:0000 - $F7:FFFF
	\|-		\|-
	\|$A0 - $FF\|\|Reserved		\|$A0 - $FF\|\|Reserved
			\|
	\|		\|
	\|-		\|-
	! colspan="3" \|''<u>Core2x expansion</u>''		! colspan="3" \|''<u>Core2x expansion</u>''
			!
	\|-		\|-
	\|$100 - $13F		\|$100 - $13F
	\|512K SRAM Page 1		\|512K SRAM Page 1
	\|SRAM_EN		\|SRAM_EN
			\|$08:0000 - $0F:FFFF
	\|-		\|-
	\|$140 - $1FF		\|$140 - $1FF
	\|Mirror of Flash, Cart, Reserved		\|Mirror of Flash, Cart, Reserved
			\|
	\|		\|
	\|-		\|-
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	\|512K SRAM Page 2		\|512K SRAM Page 2
	\|SRAM_EN		\|SRAM_EN
			\|$10:0000 - $17:FFFF
	\|-		\|-
	\|$240 - $2FF		\|$240 - $2FF
	\|Mirror of Flash, Cart, Reserved		\|Mirror of Flash, Cart, Reserved
			\|
	\|		\|
	\|-		\|-
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	\|512K SRAM Page 3		\|512K SRAM Page 3
	\|SRAM_EN		\|SRAM_EN
			\|$18:0000 - $1F:FFFF
	\|-		\|-
	\|$340 - $3FF		\|$340 - $3FF
	\|Mirror of Flash, Cart, Reserved		\|Mirror of Flash, Cart, Reserved
			\|
	\|		\|
	\|}		\|}
Line 365:		Line 377:
	The following table shows which block number has to be written into a slot register to make the each 8 KB block of memory available to the CPU.		The following table shows which block number has to be written into a slot register to make the each 8 KB block of memory available to the CPU.

	Note that since Flash & Expansion are mirrored across all 4 Core2x expansion ranges, MMU blocks $40, $140, $240, $340 all point to the same ~~physical~~ flash, and $80, $180, $280, $380 all point to the same ~~physical~~ expansion addresses.		Note that since Flash & Expansion are mirrored across all 4 Core2x expansion ranges, MMU blocks $40, $140, $240, $340 all point to the same flash addresses, and $80, $180, $280, $380 all point to the same expansion addresses.

	{\| class="wikitable" style="border: none; background: none;"		{\| class="wikitable" style="border: none; background: none;"

WF: /* Memory Block Tables */ Fixing memory block tables

2026-02-21T17:39:16Z

Memory Block Tables: Fixing memory block tables

Show changes

WF: /* Memory Block Tables */ Fixing memory block tables

2026-02-21T17:30:53Z

Memory Block Tables: Fixing memory block tables

Show changes

← Older revision		Revision as of 23:58, 21 February 2026
Line 590:		Line 590:
	\|-		\|-
	! scope=col \| Block Number		! scope=col \| Block Number
	! scope=col \| SRAM Address		! scope=col \| Flat/SRAM Address

	! scope=col \| Block Number		! scope=col \| Block Number
	! scope=col \| SRAM Address		! scope=col \| Flat/SRAM Address

	! scope=col \| Block Number		! scope=col \| Block Number
	! scope=col \| SRAM Address		! scope=col \| Flat/SRAM Address
	\|-		\|-
	\|$100\|\|$08:0000 - $08:1FFF\|\|$200\|\|$10:0000 - $10:1FFF\|\|$300\|\|$18:0000 - $18:1FFF		\|$100\|\|$08:0000 - $08:1FFF\|\|$200\|\|$10:0000 - $10:1FFF\|\|$300\|\|$18:0000 - $18:1FFF

← Older revision		Revision as of 15:41, 21 February 2026
Line 422:		Line 422:
	\|-		\|-
	! scope="col" \| Block Number		! scope="col" \| Block Number
	! scope="col" \| Flat Address		! scope="col" \| Flat/SRAM Address

	! scope="col" \| Block Number		! scope="col" \| Block Number
Line 568:		Line 568:
	\|-		\|-
	! scope=col \| Block Number		! scope=col \| Block Number
	! scope=col \| ~~Flat~~ Address		! scope=col \| SRAM Address

	! scope=col \| Block Number		! scope=col \| Block Number
	! scope=col \| ~~Flat~~ Address		! scope=col \| SRAM Address

	! scope=col \| Block Number		! scope=col \| Block Number
	! scope=col \| ~~Flat~~ Address		! scope=col \| SRAM Address
	\|-		\|-
	\|$100\|\|$08:0000 - $08:1FFF\|\|$200\|\|$10:0000 - $10:1FFF\|\|$300\|\|$18:0000 - $18:1FFF		\|$100\|\|$08:0000 - $08:1FFF\|\|$200\|\|$10:0000 - $10:1FFF\|\|$300\|\|$18:0000 - $18:1FFF