Zilog Z8F0130 - Manual (Page 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