Zilog Z8F0130 - Manual (Page 96)

eZ8
™
CPU Core
User Manual
UM012820-0810 ADD Instruction
81
Escaped Mode Addressing
Using Escaped Mode Addressing, address modes R or IR can specify a
working register. If the high nibble of the source or destination address is
Eh ( 1110b ), a working register is inferred. For example, if Working Reg-
ister R12 ( Ch ) is the preferred destination operand, use ECh as the destina-
tion operand in the Op Code. To access registers with addresses E0h to
EFh , either set the Working Group Pointer, RP[7:4] , to Eh or use indirect
addressing.
Sample Usage
If Working Register R3 contains the value 16h and Working Register R11
contains the value 20h , the following statement leaves the value 36h in
Working Register R3 and clears the C, Z, S, V, D, and H flags:
ADD R3, R11

Object Code: 02 3B
If Working Register R15 contains the value 16h , Working Register R10
contains 20h , and Register 20h contains the value 11h , the following
statement leaves the value 27h in Working Register R15 and clears the C,
Z, S, V, D, and H flags:
ADD R15, @R10

Object Code: 03 FA
ADD R1, R2 04 R2 R1 —
ADD R1, @R2 05 R2 R1 —
ADD R1, IM 06 R1 IM —
ADD @R1, IM 07 R1 IM —
Mnemonic
Destination,
Source
Op
Code
(Hex)
Operand 1 Operand 2 Operand 3