Zilog Z8F0130 - Manual (Page 121)

eZ8
™
CPU Core
User Manual
UM012820-0810 BTJNZ Instruction
106
BTJNZ
Definition
Bit Test and Jump if Non-Zero.
Syntax
BTJNZ bit, src, DA
Operation
if src[bit] = 1 {

PC
 PC + X
}
where the jump offset, X, is calculated by the eZ8 CPU assembler from
the Program Counter (PC) value and the Destination Address (DA).
Description
For this new eZ8 instruction, the selected bit in the source operand or reg-
ister pointed to by the source operand is compared with the a logical 1. If
the selected bit is 1, the signed destination displacement (X) is added to
the Program Counter, that causes a jump. The displacement value can be
from –128 to +127. This instruction tests only a single bit position. Multi-
ple bits cannot be tested simultaneously.
Table 22. BTJNZ Operand Description
Bit Position Tested Operand[3:0]
Decimal Binary Binary Hexadecimal
0 000 1000 8
1 001 1001 9
2 010 1010 A
3 011 1011 B
4 100 1100 C