Zilog Z8F0130 - Manual (Page 248)

eZ8
™
CPU Core
User Manual
UM012820-0810 SUB Instruction
233
Attributes
Escaped Mode Addressing
Using Escaped Mode Addressing, address modes R or IR specify a work-
ing register. If the high nibble of the source or destination address is
Eh
( 1110b ), a working register is inferred. For example, if Working Register
R12 ( Ch ) is the preferred destination operand, use ECh as the destination
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 F6h
in Working Register R3, sets the C, S, and D flags and clears the Z, V, and
H flags:
SUB R3, R11

Object Code: 22 3B
If Working Register R15 contains the value 16h , Working Register R10
contains the value 20h , and Register 20h contains the value 11h , the fol-
lowing statement leaves the value 05h in Working Register R15:
Mnemonic
Destination,
Source
Op
Code
(Hex)
Operand 1 Operand 2 Operand 3
SUB r1, r2 22 {r1, r2} — —
SUB r1, @r2 23 {r1, r2} — —
SUB R1, R2 24 R2 R1 —
SUB R1, @R2 25 R2 R1 —
SUB R1, IM 26 R1 IM —
SUB @R1, IM 27 R1 IM —