Zilog Z8F0130 Instrukcja Użytkownika Pobierz pdf (Strona 126)

eZ8

™

CPU Core

User Manual

UM012820-0810 BTJZ Instruction

111

It causes a Program Counter jump to occur because bit 3 of Working Reg-

ister R7 passes the test for a 0. The next instruction executed after the BTJ

is the LD instruction. The CPU assembler automatically calculates the

appropriate displacement value of

01h to allow the Program Counter to

skip the one byte HALT instruction and jump to the NEXT label that

identifies the LD instruction address. The flags are unaffected.

If Working Register R7 contains the value A5h, and register A5h contains

the value

20h (00100000b), the BTJZ instruction that begins the follow-

ing code segment does not cause a Program Counter jump to occur

because bit 5 of Register

A5h fails the test for a 0.

The next instruction executed after the BTJZ is the HALT instruction. The

flags are unaffected.

Assembly Code Object Code

BTJZ 3, r7, NEXT F6 37 01

HALT 7F

NEXT: This label is not assembled, but used by the

assembler to identify the destination address

(the address of the next instruction).

LD r0, @r2 E3 02

Assembly Code Object Code

BTJZ 5, @r7, NEXT F7 57 01

HALT 7F

NEXT: This label is not assembled, but used by the

assembler to identify the destination address (the

address of the next instruction).

LD r0, @r2 E3 02

1 2 ... 121 122 123 124 125 126 127 128 129 130 131 ... 313 314

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Zilog Z8F0130 Instrukcja Użytkownika Strona 126