debugging breakpoint (break)


	bstatus ←status
	PIE ← 0
	U ← 0
	ba ← PC + 4
	PC ← break handler address

Assembler Syntax:

      break imm5

Example: break

Description: Breaks program execution and transfers control to the debugger break-processing routine. Saves the address of the next instruction in register ba and saves the contents of the status register in bstatus. Disables interrupts, then transfers execution to the break handler.

The 5-bit immediate field imm5 is ignored by the processor, but it can be used by the debugger.

break with no argument is the same as break 0.

Usage: break is used by debuggers exclusively. Only debuggers should place break in a user program, operating system, or exception handler. The address of the break handler is specified at system generation time.

Some debuggers support break and break 0 instructions in source code. These debuggers treat the break instruction as a normal breakpoint.

Instruction Type:   R

Instruction Fields:

IMM5 = Type of breakpoint  = 0x1e 
OPX = 0x34 
OPA = 0x3a

Maintained by John Loomis, last updated 5 Feb 2007