Difference between revisions of "NDMA Registers"

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== Registers ==
 
== Registers ==
 
{| class="wikitable" border="1"
 
{| class="wikitable" border="1"
−
!  NAME
+
!  Old3DS
−
!  ADDRESS
+
!  Name
−
!  WIDTH
+
!  Address
 +
!  Width
 +
!  Used by
 
|-
 
|-
−
|  REG_NDMAGCNT
+
| style="background: green" | Yes
 +
|  [[#NDMA_GLOBAL_CNT|NDMA_GLOBAL_CNT]]
 
|  0x10002000
 
|  0x10002000
 
|  4
 
|  4
 +
|
 
|-
 
|-
−
|  REG_NDMASAD(n)
+
| style="background: green" | Yes
 +
|  [[#NDMA_SRC_ADDR|NDMA_SRC_ADDR]](n)
 
|  0x10002004 + (n*0x1c)
 
|  0x10002004 + (n*0x1c)
 
|  4
 
|  4
 +
|
 
|-
 
|-
−
|  REG_NDMADAD(n)
+
| style="background: green" | Yes
 +
|  [[#NDMA_DST_ADDR|NDMA_DST_ADDR]](n)
 
|  0x10002008 + (n*0x1c)
 
|  0x10002008 + (n*0x1c)
 
|  4
 
|  4
 +
|
 
|-
 
|-
−
|  REG_NDMATCNT(n)
+
| style="background: green" | Yes
 +
|  [[#NDMA_TRANSFER_CNT|NDMA_TRANSFER_CNT]](n)
 
|  0x1000200c + (n*0x1c)
 
|  0x1000200c + (n*0x1c)
 
|  4
 
|  4
 +
|
 
|-
 
|-
−
|  REG_NDMAWCNT(n)
+
| style="background: green" | Yes
 +
|  [[#NDMA_WRITE_CNT|NDMA_WRITE_CNT]](n)
 
|  0x10002010 + (n*0x1c)
 
|  0x10002010 + (n*0x1c)
 
|  4
 
|  4
 +
|
 
|-
 
|-
−
|  REG_NDMABCNT(n)
+
| style="background: green" | Yes
 +
|  [[#NDMA_BLOCK_CNT|NDMA_BLOCK_CNT]](n)
 
|  0x10002014 + (n*0x1c)
 
|  0x10002014 + (n*0x1c)
 
|  4
 
|  4
 +
|
 
|-
 
|-
−
|  REG_NDMAFDATA(n)
+
| style="background: green" | Yes
 +
|  [[#NDMA_FILL_DATA|NDMA_FILL_DATA]](n)
 
|  0x10002018 + (n*0x1c)
 
|  0x10002018 + (n*0x1c)
 
|  4
 
|  4
 +
|
 
|-
 
|-
−
|  REG_NDMACNT(n)
+
| style="background: green" | Yes
 +
|  [[#NDMA_CNT|NDMA_CNT]](n)
 
|  0x1000201C + (n*0x1c)
 
|  0x1000201C + (n*0x1c)
 
|  4
 
|  4
 +
|
 
|}
 
|}
  
−
== REG_NDMAGCNT ==
+
== NDMA_GLOBAL_CNT ==
 
{| class="wikitable" border="1"
 
{| class="wikitable" border="1"
 
!  BIT
 
!  BIT
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|}
 
|}
  
−
== REG_NDMASAD ==
+
== NDMA_SRC_ADDR ==
 
{| class="wikitable" border="1"
 
{| class="wikitable" border="1"
 
!  BIT
 
!  BIT
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|  Source data address. Must be multiple of 4.
 
|  Source data address. Must be multiple of 4.
 
|}
 
|}
−
Like old DMA, REG_NDMASAD is copied to internal registers when written to.
+
Like old DMA, NDMA_SRC_ADDR is copied to internal registers when written to.
  
−
== REG_NDMADAD ==
+
== NDMA_DST_ADDR ==
 
{| class="wikitable" border="1"
 
{| class="wikitable" border="1"
 
!  BIT
 
!  BIT
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|  Destination data address. Must be multiple of 4.
 
|  Destination data address. Must be multiple of 4.
 
|}
 
|}
−
Like old DMA, REG_NDMADAD is copied to internal registers when written to.
+
Like old DMA, NDMA_DST_ADDR is copied to internal registers when written to.
  
−
== REG_NDMATCNT ==
+
== NDMA_TRANSFER_CNT ==
 
{| class="wikitable" border="1"
 
{| class="wikitable" border="1"
 
!  BIT
 
!  BIT
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|}
 
|}
  
−
== REG_NDMAWCNT ==
+
== NDMA_WRITE_CNT ==
 
{| class="wikitable" border="1"
 
{| class="wikitable" border="1"
 
!  BIT
 
!  BIT
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|}
 
|}
  
−
== REG_NDMABCNT ==
+
== NDMA_BLOCK_CNT ==
 
{| class="wikitable" border="1"
 
{| class="wikitable" border="1"
 
!  BIT
 
!  BIT
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|}
 
|}
  
−
== REG_NDMAFDATA ==
+
== NDMA_FILL_DATA ==
 
{| class="wikitable" border="1"
 
{| class="wikitable" border="1"
 
!  BIT
 
!  BIT
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|}
 
|}
  
−
== REG_NDMACNT ==
+
== NDMA_CNT ==
 
{| class="wikitable" border="1"
 
{| class="wikitable" border="1"
 
!  BIT
 
!  BIT
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== Block transfers ==
 
== Block transfers ==
−
First, a word is always 32 bits. Second, the block transfer specified in REG_NDMACNT is the smallest atom of data that will be transferred in a burst. The bus is monopolized until this block is transferred, without splitting up.
+
First, a word is always 32 bits. Second, the block transfer specified in NDMA_CNT is the smallest atom of data that will be transferred in a burst. The bus is monopolized until this block is transferred, without splitting up.
  
−
The next block transfer will happen after the specified time in the REG_NDMABCNT interval timer, until done.
+
The next block transfer will happen after the specified time in the NDMA_BLOCK_CNT interval timer, until done.
  
 
== Immediate mode ==
 
== Immediate mode ==
−
Transfers the words specified in REG_NDMAWCNT immediately following block transfer rules. REG_NDMATCNT and repeating mode are ignored.
+
Transfers the words specified in NDMA_WRITE_CNT immediately following block transfer rules. NDMA_TRANSFER_CNT and repeating mode are ignored.
  
 
== Repeating mode ==
 
== Repeating mode ==
−
Transfers the words specified in REG_NDMAWCNT following the startup mode event. REG_DMATCNT is ignored.
+
Transfers the words specified in NDMA_WRITE_CNT following the startup mode event. NDMA_TRANSFER_CNT is ignored.
  
 
== No immediate and no repeating mode ==
 
== No immediate and no repeating mode ==
−
Transfers the words specified in REG_NDMAWCNT for each startup event, and gets disabled when the total number of words in REG_NDMATCNT are transferred.
+
Transfers the words specified in NDMA_WRITE_CNT for each startup event, and gets disabled when the total number of words in NDMA_TRANSFER_CNT are transferred.

Revision as of 22:40, 19 March 2015

3DS NDMA has 8 channels. The first 0x100-bytes of this IO mem is mirrored at 0x10002100, repeated every 0x100-bytes until the end of the 0x1000-byte IO mem.

Registers

Old3DS Name Address Width Used by
Yes NDMA_GLOBAL_CNT 0x10002000 4
Yes NDMA_SRC_ADDR(n) 0x10002004 + (n*0x1c) 4
Yes NDMA_DST_ADDR(n) 0x10002008 + (n*0x1c) 4
Yes NDMA_TRANSFER_CNT(n) 0x1000200c + (n*0x1c) 4
Yes NDMA_WRITE_CNT(n) 0x10002010 + (n*0x1c) 4
Yes NDMA_BLOCK_CNT(n) 0x10002014 + (n*0x1c) 4
Yes NDMA_FILL_DATA(n) 0x10002018 + (n*0x1c) 4
Yes NDMA_CNT(n) 0x1000201C + (n*0x1c) 4

NDMA_GLOBAL_CNT

BIT DESCRIPTION
19-16 Cycle selection.
31 DMA arbitration method. 0=Fixed method, 1=Round robin

NDMA_SRC_ADDR

BIT DESCRIPTION
31-0 Source data address. Must be multiple of 4.

Like old DMA, NDMA_SRC_ADDR is copied to internal registers when written to.

NDMA_DST_ADDR

BIT DESCRIPTION
31-0 Destination data address. Must be multiple of 4.

Like old DMA, NDMA_DST_ADDR is copied to internal registers when written to.

NDMA_TRANSFER_CNT

BIT DESCRIPTION
27-0 Total number of words transferred.

NDMA_WRITE_CNT

BIT DESCRIPTION
23-0 Number of words to transfer.

NDMA_BLOCK_CNT

BIT DESCRIPTION
15-0 Interval timer.
17-16 Prescaler. 0=System freq, 1=1/4th freq, 2=1/16th freq, 3=1/64th freq.

NDMA_FILL_DATA

BIT DESCRIPTION
31-0 Fill data.

NDMA_CNT

BIT DESCRIPTION
11-10 Destination address update method. 0=Increment, 1=Decrement, 2=Fixed.
12 Destination address reload flag.
14-13 Source address update method. 0=Increment, 1=Decrement, 2=Fixed, 3=No address (for filling)
15 Source address reload flag.
19-16 Block transfer word count = (1<<x) words.
27-24 Startup mode.
28 Immediate mode.
29 Repeating mode.
30 IRQ enable
31 Enable/busy flag.


Startup modes (27-24)

???

Block transfers

First, a word is always 32 bits. Second, the block transfer specified in NDMA_CNT is the smallest atom of data that will be transferred in a burst. The bus is monopolized until this block is transferred, without splitting up.

The next block transfer will happen after the specified time in the NDMA_BLOCK_CNT interval timer, until done.

Immediate mode

Transfers the words specified in NDMA_WRITE_CNT immediately following block transfer rules. NDMA_TRANSFER_CNT and repeating mode are ignored.

Repeating mode

Transfers the words specified in NDMA_WRITE_CNT following the startup mode event. NDMA_TRANSFER_CNT is ignored.

No immediate and no repeating mode

Transfers the words specified in NDMA_WRITE_CNT for each startup event, and gets disabled when the total number of words in NDMA_TRANSFER_CNT are transferred.

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