Halt Breakpoint (HBK)/OP=48



OP = 48

The final AF value is ignored, but is useful to identify a specific breakpoint. May specify indirect field length. However, the specification of an AF indirect field length may produce incompatible results (see Compatibility Notes A.25).
The BF field is an eight bit breakpoint control mask. The field will not be recognized as indirect.


The Halt Breakpoint instruction performs a mask test against a halt character in memory location 46 relative to base #0. If a bit is set in the halt character that corresponds to a bit set in the mask, the instruction executes a halt according to the halt digit in absolute memory address 48. See Compatibility Notes A.25.1).

If there is no correspondence between the bits in the mask and the bits in the breakpoint bit pattern, the next instruction is executed in normal sequence with no other significant action.

Comparison Flags

The Comparison Flags are not modified by this instruction.


There are no overlap restrictions for this instruction.

instructions/hbk.txt · Last modified: 2008/11/25 14:29 by scott
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