Zilog Z8F0130 Manual do Utilizador descarregar pdf (Página 240)

eZ8

™

CPU Core

User Manual

UM012820-0810 SRA Instruction

225

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 Working Register R6 contains the value 31h (00110001b), the follow-

ing statement leaves the value 18h (00011000b) in Working Register R6,

sets the Carry flag, and clears the Z, V, and S flags:

SRA R6



Object Code: D0 E6

If Register C6h contains the value DFh, and Register DFh contains the

value

B8h (10111000b), the following statement leaves the value DCh

(

11011100b) in Register DFh, resets the C, Z and V flags and sets the S

flag:

SRA @C6h



Object Code: D1 C6

Mnemonic Destination

Code

(Hex) Operand 1 Operand 2 Operand 3

SRA R1 D0 R1 — —

SRA @R1 D1 R1 — —

1 2 ... 235 236 237 238 239 240 241 242 243 244 245 ... 313 314

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