NEC V850/SF1 - Manual (Page 24)

User’s Manual U15447EJ1V0UM
24
CHAPTER 4 CAUTIONS
4.1 V
DD0
and PORTV
DD
of Target System
(1) V DD0 in the target system is used to sense the level for target system power supply ON/OFF.
• When V
DD0
is lower than 1 V, it is judged that the target system is not connected, and mapping of the target
memory cannot be performed with a debugger (FCAN cannot be used).
• When V
DD0
is 1 V or higher, it is judged that the target system is connected, and mapping of the target
memory can be performed with a debugger (FCAN can be used).
(2) PORTV DD in the target system is not supplied directly to the emulator chip; it is connected to the target voltage
emulation circuit.
• When PORTV
DD is lower than 3 V, V CC (5 V) in the internal emulator is supplied to the emulator chip.
• When PORTV
DD is 3 V or higher, a voltage of the same potential as PORTV DD in the target system is
generated and supplied to the emulator chip.
Figure 4-1. Schematic Diagram of Power Supply Acquisition
Relay
V850/SF1
I/O chip
Target voltage
emulation
ON/OFF?
Evaluation
chip
Target
system
V CC (5 V)
PORTV DD
(66 pins)
V
DD
(8 pins)
IE-703079-MC-EM1 IE-703002-MC