CHAPTER 4 DIFFERENCES BETWEEN TARGET DEVICES AND TARGET INTERFACE CIRCUITS
User’s Manual U13742EJ2V0UM
39
Figure 4-4. Equivalent Circuit 4 of Emulation Circuit
V
CC
4.7 k
Ω
10 M
Ω
470 k
Ω
VHC244
XT1
XT2
(Open)
TEST/V
PP
TEST/V
PP
XT1
JP1
V
CC
4.7 k
Ω
1 M
Ω
1
2
3
IC socket
HC4053
HCU04
HCU04
6
8
22 pF
22 pF
32.768 kHz
IE-78K4-NS side
Probe side
The internal IE system voltage is selected for the TEST/V
PP
input to the IE system during reset. The voltage from
the target is selected after reset is released.
(3) Other signals
•
V
DD
pin
When the emulation CPU is operating at 5 V, its power is supplied from the internal IE system, but when
operating at low voltage, its power is supplied from the low-voltage pin (TP1). The V
DD
pin of the target system
is only used to control the LED (USERV
DD
) in the IE system that monitors the input of the target system’s power
supply.
•
V
SS
pin
The V
SS
pin is connected to GND inside the IE system.
