Epson S1C62 Family 2.3.7History function, 2.3.6Target interrupt and break, *PC=0000 A=.... F=.DZC X=000 Y=010

ICE CONTROL SOFTWARE ICS62XX

2.3.6Target interrupt and break

When a target interrupt occurs the moment of a break it is given priority over the break. The break is then induced after the interrupt process is stacked. Next, the interrupt routine is executed from the top when the run mode commences.

The PC displayed during a break is the top interrupt address.

When a break is set by the BR command with FI=1, the break and interrupt are generated simultaneously, but due to the interrupt process, the register values after the break are:

*PC=0000 A=.... F=.DZC X=000 Y=010

FI reset

so as to reset the FI flag status.

2.3.7History function

The evaluation board CPU information (PC, instruction code, RAM data address and data content, and CPU internal registers) while running an emulation are fetched to the history memory region with each CPU bus cycle. The history memory has a capacity of 8291 cycles, and can store 2730 (5 clock instructions only) to 1365 (12 clock instructions only) new instructions executed by the evaluation board.

	History memory			History memory
			Oldest instruction
			(HP=0)		Effective	(HP=2730)
		Effective			history	Instruction
						immediately
		history				prior to break
						Oldest instruction
						(HP=0)
Program
execution			Instruction		Effective
			immediately		history
		Space	prior to break
			(HP=700)

Fig. 2.3.7.1 History function diagram

Figure 2.3.7.1 shows a diagram of the history function. When the history memory is filled, old data is overwritten by new data.

The history pointer (HP) normally displays the oldest instruction at position 0, but during a break it displays the newest instruction. The maximum value of the HP is about 2730 when 5 clock instructions are executed.

History data

HP=0

Oldest

instruction

The HP can display optional positions via the H, HB, and HG commands.

HP data from 1980 to 1986 is displayed by entering: #H, 1980, 1986

Newest

HP=2700 instruction

Fig. 2.3.7.2 History data display

VIII-14	EPSON	S1C62 FAMILY
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