Zilog Z8F0130 - Manual (Page 233)

eZ8
™
CPU Core
User Manual
UM012820-0810 SBC Instruction
218
Attributes
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 , the Carry flag is 1, and
Working Register R11 contains the value 20h , the following statement
leaves the value F5h in Working Register R3, sets the C, S, and D flags
and clears the Z, V, and H flags:
SBC R3, R11

Object Code: 32 3B
If Working Register R15 contains the value 16h , the Carry flag is not set,
Working Register R10 contains the value 20h , and Register 20h contains
the value 11h , the following statement leaves the value 05h in Working
Register R15, sets the D flag, and clears the C, Z, S, V, and H flags:
Mnemonic
Destination,
Source
Op
Code
(Hex)
Operand 1 Operand 2 Operand 3
SBC r1, r2 32 {r1, r2} — —
SBC r1, @r2 33 {r1, r2} — —
SBC R1, R2 34 R2 R1 —
SBC R1, @R2 35 R2 R1 —
SBC R1, IM 36 R1 IM —
SBC @R1, IM 37 R1 IM —