Zilog Z8F0130 - Manual (Page 123)

eZ8
™
CPU Core
User Manual
UM012820-0810 BTJNZ Instruction
108
causes a Program Counter jump to occur because bit 5 of Working Regis-
ter R7 passes the test for a 1. The next instruction executed after the
BTJNZ is the LD instruction. The eZ8 CPU assembler automatically cal-
culates the appropriate displacement value of
01h , allowing 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 BTJNZ instruction that begins the fol-
lowing code segment:
It does not cause a Program Counter jump to occur because bit 3 of Regis-
ter
A5h fails the test for a 1. The next instruction executed after the
BTJNZ is the HALT instruction. The flags are unaffected.
Assembly Code Object Code
BTJNZ 5, r7, NEXT F6 D7 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
BTJNZ 3, @r7, NEXT F7 B7 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