Absolute Boolean Bit Addressing: Difference between revisions

Latest revision as of 14:25, 1 August 2024

Absolute Boolean Bit is used on the SPC700 by some three-byte instructions to address individual bits:

The bottom 13 bits of a 16-bit value specify an absolute address, while the top 3 bits specify which bit within the byte stored at that address. The greatest address these instructions can affect is 1FFFh.

Syntax

AND1 C, mem. bit
AND1 C, /mem. bit
OR1 C, mem. bit
OR1 C, /mem. bit
EOR1 C, mem. bit
MOV1 C, mem. bit
MOV1 mem. bit, C
NOT1 mem. bit

References

page 3-8-8 of Book I of the official Super Nintendo development manual
Figure 3-8-3 Memory Access Addressing Effective Address on page 3-8-9, lbid.

@@ Line 1: / Line 1: @@
-'''13-bit Absolute Addressing''' is used on the [[SPC700]] by some instructions to address individual bits:
+'''Absolute Boolean Bit''' is used on the [[SPC700]] by some three-byte instructions to address individual bits:
 * [[AND1]]
@@ Line 7: / Line 7: @@
 * [[NOT1]]
-The bottom 13 bits of a 16-bit value specify an absolute address, while the top 3 bits specify which bit within the byte stored at that address.
+The bottom 13 bits of a 16-bit value specify an absolute address, while the top 3 bits specify which bit within the byte stored at that address.  The greatest address these instructions can affect is 1FFFh.
+==== Syntax ====
+<pre>
+AND1 C, mem. bit
+AND1 C, /mem. bit
+OR1 C, mem. bit
+OR1 C, /mem. bit
+EOR1 C, mem. bit
+MOV1 C, mem. bit
+MOV1 mem. bit, C
+NOT1 mem. bit
+</pre>
 === See Also ===
 * [[Absolute Addressing]]
+* [[Direct Page Bit Addressing]]
+=== References ===
+* [https://archive.org/details/SNESDevManual/book1/page/n186 page 3-8-8 of Book I] of the official Super Nintendo development manual
+* Figure 3-8-3 Memory Access Addressing Effective Address on [https://archive.org/details/SNESDevManual/book1/page/n187 page 3-8-9], lbid.
 [[Category:ASM]]
 [[Category:Addressing Modes]]
-[[Category:Scene Slang]]
+[[Category:Official Jargon]]