Zilog Z8F0130 - Manual (Page 148)

eZ8
™
CPU Core
User Manual
UM012820-0810 DA Instruction
133
Attributes
Escaped Mode Addressing
Using Escaped Mode Addressing, address modes R or IR can specify a
working register. If the destination address is prefixed by
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 addition is performed using the BCD value 15 and 27, the result should
be 42. The sum is incorrect, however, when the binary representations are
added in the destination location using standard binary arithmetic.
If the result of the addition is stored in Register 5Fh , the following state-
ment adjusts this result to obtain the correct BCD representation.
DA 5Fh

Object C?de: 40 5F
Mnemonic Destination
Op
Code
(Hex)
Operand 1 Operand 2 Operand 3
DA R1 40 R1 — —
DA @R1 41 R1 — —
0001 0101 = 15h
0010 0111 = 27h
0011 1100 = 3Ch