QB-V850ESFJ3 Preliminary User’s Manual ZUD-CD-05-0149 38/57
CHAPTER 4 CAUTIONS
This chapter explains the points to be noted when the QB-V850ESFJ3 is used.
4.1 Cautions on Flash Self Programming Function
The flash self programming function cannot be emulated. To use this function, make an evaluation by using an
on-chip debug emulator or the target device.
4.2 Cautions on Non-Map Break
If a program is fetched from an area not used by a
program (unused area) with an emulator, a non-map
break usually occurs. However, a non-map break does
not occur in the first 16-byte space of each unused area
(refer to
Figure 4-1
).
4.3 Cautions on DBTRAP Instruction
The DBTRAP instruction cannot be used.
4.4 PSC Register Access
Data is written to the PSC register in the following
sequence. If a software break is set to the NOP
instruction immediately after the register has been
accessed, the debugger hangs up.
Example:
mov 0x2,r1
st.b r1,prcmd
st.b r1,psc
nop
←
Debugger hangs up if a software break is set here.
nop
←
There is no problem if a software break is set here or later.
To set a break immediately after the PSC register has been written, use a hardware break.
Figure 4-1. Break at Fetching Unused Area
Used area
(Non-map break does not occur)
Unused area
(Non-map break occurs)
Unused area
(Non-map break occurs)
Used area
(Non-map break does not occur)
16 bytes
16 bytes
Non-map break does
not occur in this area
Used area
(Non-map break does not occur)
