Samsung S3C84E5 Common Working Register Area C0H-CFH, RP1 → C8H-CFH, FFH F0H, E0H D0H C0H BFH

ADDRESS SPACES S3C84E5/C84E9/P84E9

COMMON WORKING REGISTER AREA (C0H–CFH)

After a reset, register pointers RP0 and RP1 automatically select two 8-byte register slices in set 1, locations C0H– CFH, as the active 16-byte working register block:

RP0 → C0H–C7H

RP1 → C8H–CFH

This 16-byte address range is called common area. That is, locations in this area can be used as working registers by operations that address any location on any page in the register file. Typically, these working registers serve as temporary buffers for data operations between different pages.

				FFH	Page 1
		Set 1		FFH
FFH					Page 0
F0H					Set 2
E0H
D0H				C0H
C0H				BFH	Page 0
Following a hardware reset, register							~
pointers RP0 and RP1 point to the
				~		~
common working register area,					Prime
locations C0H-CFH.					Space
RP0 =
	1 1 0 0		0 0 0 0
RP1 =
	1 1 0 0		1 0 0 0	00H

Figure 2-10. Common Working Register Area

2-14