SP0256 Page Prefix

From Intellivision Wiki

(Difference between revisions)
Jump to: navigation, search
m
Line 3: Line 3:
The Page Prefix register provides the upper 4 bits of the address for [[SP0256 JSR|JSR]] instructions, as well as branches initiated by an external [[SP0256 Address Load]] command.
The Page Prefix register provides the upper 4 bits of the address for [[SP0256 JSR|JSR]] instructions, as well as branches initiated by an external [[SP0256 Address Load]] command.
-
(Unsure:  Do JSRs push 12-bit or 16-bit addresses...?  I think they push 16-bit, so "[[SP0256 RTS|RTS]] always returns to the right place.  Need to check.)
+
(Unsure:  Do JSRs push 12-bit or 16-bit addresses...?  I think they push 16-bit, so [[SP0256 RTS|RTS]] always returns to the right place.  Need to check.)

Revision as of 22:40, 18 January 2005


The Page Prefix register provides the upper 4 bits of the address for JSR instructions, as well as branches initiated by an external SP0256 Address Load command.

(Unsure: Do JSRs push 12-bit or 16-bit addresses...? I think they push 16-bit, so RTS always returns to the right place. Need to check.)

Personal tools
Namespaces
Variants
Actions
Navigation
Toolbox