Difference between revisions of "NDMA"
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| Line 129: | Line 129: | ||
|- | |- | ||
| 19-16 | | 19-16 | ||
| − | | Block transfer word count. | + | | Block transfer word count = (1<<x) words. |
|- | |- | ||
| 27-24 | | 27-24 | ||
| Line 145: | Line 145: | ||
| 31 | | 31 | ||
| Enable/busy flag. | | Enable/busy flag. | ||
| + | |} | ||
| + | |||
| + | |||
| + | == Startup modes (27-24) == | ||
| + | {| class="wikitable" border="1" | ||
| + | ! BIT | ||
| + | ! DESCRIPTION | ||
| + | |- | ||
| + | | 0 | ||
| + | | Timer 0 | ||
| + | |- | ||
| + | | 1 | ||
| + | | Timer 1 | ||
| + | |- | ||
| + | | 2 | ||
| + | | Timer 2 | ||
| + | |- | ||
| + | | 3 | ||
| + | | Timer 3 | ||
| + | |- | ||
| + | | 4 | ||
| + | | Game Card | ||
| + | |- | ||
| + | | 6 | ||
| + | | V-Blank | ||
| + | |- | ||
| + | | 7 | ||
| + | | H-Blank | ||
| + | |- | ||
| + | | 8 | ||
| + | | Display | ||
| + | |- | ||
| + | | 9 | ||
| + | | Work RAM | ||
| + | |- | ||
| + | | 10 | ||
| + | | Geometry FIFO | ||
| + | |- | ||
| + | | 11 | ||
| + | | Camera | ||
|} | |} | ||
Revision as of 06:31, 25 November 2010
Registers
There's 4 NDMA channels. Arm7/Arm9 have separate NDMA.
| NAME | ADDRESS | WIDTH |
|---|---|---|
| REG_NDMAGCNT | 0x04004100 | 4 |
| REG_NDMASAD(n) | 0x04004104 + (n*0x1c) | 4 |
| REG_NDMADAD(n) | 0x04004108 + (n*0x1c) | 4 |
| REG_NDMATCNT(n) | 0x0400410c + (n*0x1c) | 4 |
| REG_NDMAWCNT(n) | 0x04004110 + (n*0x1c) | 4 |
| REG_NDMABCNT(n) | 0x04004114 + (n*0x1c) | 4 |
| REG_NDMAFDATA(n) | 0x04004118 + (n*0x1c) | 4 |
| REG_NDMACNT(n) | 0x0400411c + (n*0x1c) | 4 |
REG_NDMAGCNT
| BIT | DESCRIPTION |
|---|---|
| 19-16 | Cycle selection. |
| 31 | DMA arbitration method. 0=Fixed method, 1=Round robin |
REG_NDMASAD
| BIT | DESCRIPTION |
|---|---|
| 31-0 | Source data address. Must be multiple of 4. |
Like old DMA, REG_NDMASAD is copied to internal registers when written to.
REG_NDMADAD
| BIT | DESCRIPTION |
|---|---|
| 31-0 | Destination data address. Must be multiple of 4. |
Like old DMA, REG_NDMADAD is copied to internal registers when written to.
REG_NDMATCNT
| BIT | DESCRIPTION |
|---|---|
| 27-0 | Total number of words transferred. |
REG_NDMAWCNT
| BIT | DESCRIPTION |
|---|---|
| 23-0 | Number of words to transfer. |
REG_NDMABCNT
| BIT | DESCRIPTION |
|---|---|
| 15-0 | Interval timer. |
| 17-16 | Prescaler. 0=System freq, 1=1/4th freq, 2=1/16th freq, 3=1/64th freq. |
REG_NDMAFDATA
| BIT | DESCRIPTION |
|---|---|
| 31-0 | Fill data. |
REG_NDMACNT
| BIT | DESCRIPTION |
|---|---|
| 11-10 | Destination address update method. |
| 12 | Destination address reload flag. |
| 14-13 | Source address update method. |
| 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)
| BIT | DESCRIPTION |
|---|---|
| 0 | Timer 0 |
| 1 | Timer 1 |
| 2 | Timer 2 |
| 3 | Timer 3 |
| 4 | Game Card |
| 6 | V-Blank |
| 7 | H-Blank |
| 8 | Display |
| 9 | Work RAM |
| 10 | Geometry FIFO |
| 11 | Camera |