Difference between revisions of "84PCE:Syscalls:0210DC"
From WikiTI
(Created page with "MemClear MemClear 4C30 - MemClear == Synopsis == '''Offi...") |
|||
| (7 intermediate revisions by one other user not shown) | |||
| Line 1: | Line 1: | ||
| − | [[Category:84PCE:Syscalls: | + | [[Category:84PCE:Syscalls:By Name:Memory|MemClear]] |
| − | [[Category:84PCE:Syscalls: | + | [[Category:84PCE:Syscalls:By Name|MemClear]] |
| − | [[Category:84PCE:Syscalls: | + | [[Category:84PCE:Syscalls:By Address|0210DC - MemClear]] |
== Synopsis == | == Synopsis == | ||
| Line 18: | Line 18: | ||
=== Destroys === | === Destroys === | ||
| − | * | + | * A = 0 |
| + | * HL = HL+BC | ||
| + | * DE = HL+1+BC | ||
| + | * BC = 0 | ||
== Comments == | == Comments == | ||
| − | This routine uses an LDIR instruction to clear the memory block, so do not pass it a block length of 0 or 1 or it will erase | + | This routine uses an LDIR instruction to clear the memory block, so do not pass it a block length of 0 or 1 or it will erase 16777216 bytes. |
| + | |||
| + | ''See also: [[84PCE:Syscalls:0210E0|MemSet]]'' | ||
== Example == | == Example == | ||
Latest revision as of 03:43, 16 July 2016
Synopsis
Official Name: MemClear
Syscall Address: 0210DCh
Sets a block of memory to zero.
Inputs
- HL: Address of memory block.
- BC: Number of bytes to zero.
Outputs
- DE: Points to byte after memory block.
Destroys
- A = 0
- HL = HL+BC
- DE = HL+1+BC
- BC = 0
Comments
This routine uses an LDIR instruction to clear the memory block, so do not pass it a block length of 0 or 1 or it will erase 16777216 bytes.
See also: MemSet
Example
;Clear out pixelShadow
ld hl,pixelShadow
ld bc,8400
call _MemClear
