Difference between revisions of "Clip Window Control Register"
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(Fixing read/write vs index auto increment description, thanks to Garry help on Facebook to identify the mistake) |
(fix description for core3.1.5 functionality) |
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! Bit !! Function | ! Bit !! Function | ||
|- | |- | ||
| − | | 7- | + | | 7-4 || Reserved, must be 0 |
| + | |- | ||
| + | | 3 || reset the Tilemap clip-window register index (by writing 1). | ||
|- | |- | ||
| 2 || reset the ULA/LoRes clip-window register index (by writing 1). | | 2 || reset the ULA/LoRes clip-window register index (by writing 1). | ||
| Line 22: | Line 24: | ||
! Bit !! Function | ! Bit !! Function | ||
|- | |- | ||
| − | | 7-6 || | + | | 7-6 || the current Tilemap clip-window register index |
|- | |- | ||
| − | | 5-4 || the current Layer 2 clip-window register index | + | | 5-4 || the current ULA/LoRes (<del>was Layer 2 in older cores</del>) clip-window register index |
|- | |- | ||
| 3-2 || the current Sprite clip-window register index | | 3-2 || the current Sprite clip-window register index | ||
|- | |- | ||
| − | | 1-0 || the current ULA/LoRes clip-window register index | + | | 1-0 || the current Layer 2 (<del>was ULA/LoRes in older cores</del>) clip-window register index |
|} | |} | ||
Each read index maps as 0: X1, 1: X2, 2: Y1 and 3: Y2 (the same order how the coordinates are written to particular clip-window register). | Each read index maps as 0: X1, 1: X2, 2: Y1 and 3: Y2 (the same order how the coordinates are written to particular clip-window register). | ||
Latest revision as of 20:38, 23 September 2020
| Number | $1C |
|---|---|
| Readable | Yes |
| Writable | Yes |
| Short Description | Controls (resets) the clip-window registers indices. |
Write:
| Bit | Function |
|---|---|
| 7-4 | Reserved, must be 0 |
| 3 | reset the Tilemap clip-window register index (by writing 1). |
| 2 | reset the ULA/LoRes clip-window register index (by writing 1). |
| 1 | reset the Sprite clip-window register index (by writing 1). |
| 0 | reset the Layer 2 clip-window register index (by writing 1). |
Read:
| Bit | Function |
|---|---|
| 7-6 | the current Tilemap clip-window register index |
| 5-4 | the current ULA/LoRes ( |
| 3-2 | the current Sprite clip-window register index |
| 1-0 | the current Layer 2 ( |
Each read index maps as 0: X1, 1: X2, 2: Y1 and 3: Y2 (the same order how the coordinates are written to particular clip-window register).