Zilog Z8F0130 Manual do Utilizador descarregar pdf (Página 181)

eZ8

™

CPU Core

User Manual

UM012820-0810 LD Instruction

166

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

The following statement loads the value 34h into Working Register R15.

LD R15, #

34h

Object Code: FC 34

If Register 34h contains the value FCh, the following statement loads the

value

FCh into Working Register R14.

LD R14,

34h

Object Code: E4 34 EE

The contents of Register 34h are not affected.

If Working Register R14 contains the value 45h, the following statement

loads the value

45h into Register 34h:

34h

, R14



Object Code: E4 EE 34

The contents of Working Register R14 are not affected.

If Working Register R12 contains the value 34h, and Register 34h con-

tains the value FFh, the following statement loads the value FFh into

Working Register R13:

LD R13, @R12



Object Code: E3 DC

The contents of Working Register R12 and Register R34 are not affected.

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Zilog Z8F0130 Manual do Utilizador Página 181