Differences
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| instruction_encoding [2023/12/18 12:44] – [ALU instructions] pulkomandy | instruction_encoding [2023/12/31 16:49] (current) – [ALU instructions] pulkomandy | ||
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| Line 114: | Line 114: | ||
| ^%% D: | ^%% D: | ||
| ^%% Rs %%| ALU op| Op. A | 4 | 0 | Rs | | ^%% Rs %%| ALU op| Op. A | 4 | 0 | Rs | | ||
| - | ^%% # | + | ^%% # |
| - | ^%% From [Addr16] %%| ALU op| Op. A | 4 | 2 | Rs | + | ^%% From [Addr16] %%| ALU op| Op. A | 4 | 2 | Unused |
| - | ^%% To [Addr16] | + | ^%% To [Addr16] |
| ^%% Rs ASR shift %%| ALU op| Op. A | 4 | 4 + (shift - 1) | Rs | | ^%% Rs ASR shift %%| ALU op| Op. A | 4 | 4 + (shift - 1) | Rs | | ||
| ^%% Rs LSL shift %%| ALU op| Op. A | 5 | shift - 1 | Rs | | ^%% Rs LSL shift %%| ALU op| Op. A | 5 | shift - 1 | Rs | | ||
| Line 142: | Line 142: | ||
| '' | '' | ||
| - | and the "To [Addr16"]'' | + | and the "To [Addr16]" |
| - | '' | + | '' |
| + | |||
| + | (so in this case the register encoded in OPA is used as a source, not a destination). | ||
| The LD and ST operations with the 16-bit addressing mode ignore the value of Rs, they use only Ra and the 16-bit value. | The LD and ST operations with the 16-bit addressing mode ignore the value of Rs, they use only Ra and the 16-bit value. | ||
