diff options
| author | mrb0nk500 <b0nk@b0nk.xyz> | 2019-12-01 17:40:41 -0500 |
|---|---|---|
| committer | mrb0nk500 <b0nk@b0nk.xyz> | 2019-12-02 18:10:41 -0500 |
| commit | cbad8aabbc82efbe7a49572a2da74224ae9c9f85 (patch) | |
| tree | e97b1ab35208bc3e4d633f235d875fd4c69d039f /test | |
| parent | ca89989d057a19b647514656d96d00ff23be9640 (diff) | |
Added the ability to disable the prefix byte.
Any instructions that either have a register size of
8 bits, use implied addressing, or branch can save a
byte by disabling the prefix byte.
It does this by checking if the first three bits are
all set to 1.
If true, then it will treat it as a prefix
byte, otherwise, it will treat it as an opcode.
Diffstat (limited to 'test')
| -rw-r--r-- | test/test-no-prefix.s | 8 | ||||
| -rw-r--r-- | test/test.s | 2 |
2 files changed, 9 insertions, 1 deletions
diff --git a/test/test-no-prefix.s b/test/test-no-prefix.s new file mode 100644 index 0000000..3c9c6a9 --- /dev/null +++ b/test/test-no-prefix.s @@ -0,0 +1,8 @@ +cps +lda #$10 +rol #$1 +jmp $3 +;viewmem +;q +done + diff --git a/test/test.s b/test/test.s index 3e8a7f2..7c36579 100644 --- a/test/test.s +++ b/test/test.s @@ -5,7 +5,7 @@ cps ; Clear the processor status register. lda.w #$1000 ; Load 0x1000 into the accumulator. rol #$1 ; Then rotate the accumulator left by 1 bit. -jmp $8006 ; And then loop. +jmp $8005 ; And then loop. .org $FFC0 ; Reset vector. .qword $8000 |