LD pd,ps+DE     Load     Rabbit 4000 Instruction

Opcode	Instruction	Clocks	Operation
--	LD pd,ps+DE	4 (2,2)	pd = ps + DE
6D 06	LD PW,PW+DE	4 (2,2)	PW = PW + DE
6D 16	LD PW,PX+DE		PW = PX + DE
6D 26	LD PW,PY+DE		PW = PY + DE
6D 36	LD PW,PZ+DE		PW = PZ + DE
6D 46	LD PX,PW+DE	4 (2,2)	PX = PW + DE
6D 56	LD PX,PX+DE		PX = PX + DE
6D 66	LD PX,PY+DE		PX = PY + DE
6D 76	LD PX,PZ+DE		PX = PZ + DE
6D 86	LD PY,PW+DE	4 (2,2)	PY = PW + DE
6D 96	LD PY,PX+DE		PY = PX + DE
6D A6	LD PY,PY+DE		PY = PY + DE
6D B6	LD PY,PZ+DE		PY = PZ + DE
6D C6	LD PZ,PW+DE	4 (2,2)	PZ = PW + DE
6D D6	LD PZ,PX+DE		PZ = PX + DE
6D E6	LD PZ,PY+DE		PZ = PY + DE
6D F6	LD PZ,PZ+DE		PZ = PZ + DE

Flags				ALTD			IOI/IOE
S	Z	L/V	C	F	R	SP	S	D
-	-	-	-		·

Description

Loads pd (any of the 32-bit registers PW, PX, PY or PZ) with the sum of ps (any of PW, PX, PY or PZ) and DE. These instructions cannot be used for general 32-bit arithmetic because the addition depends on the upper two bytes of ps. If the upper two bytes are all ones, then it is 16-bit addition. The following example illustrates this point:

ld PW,0xFFFFFFFF
ld PW,PW+DE            ;yields PW=0xFFFF0000 if DE=1

ld PW,0x7FFFFFFF
ld PW,PW+DE            ;yields PW=0x80000000 if DE=1