User’s Manual U18172EJ2V0UD
268
CHAPTER 17 ON-CHIP DEBUG FUNCTION
17.1 Connecting QB-MINI2 to 78K0S/KU1+
The 78K0S/KU1+ uses RESET, X1, X2, INTP1, V
DD
, and GND pins to communicate with the host machine via an
on-chip debug emulator (QB-MINI2).
Caution
Do not use the on-chip debug function in products designated for mass production, because the
guaranteed number of rewritable times of the flash memory may be exceeded when this function
is used, and product reliability therefore cannot be guaranteed. NEC Electronics is not liable for
problems occurring when the on-chip debug function is used.
Figure 17-1. Recommended Circuit Connection
Target connector
Target device
Reset circuit
GND
RESET
Note 1
X2
Note 2
X1
Note 2
INTP1
Note 5
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
RESET_OUT
RESET signal
DATA
GND
DATA
R.F.U.
R.F.U.
H/S
Note 4
Note 3
Note 3
CLK
R.F.U.
R.F.U.
INTP
R.F.U.
CLK
RESET_IN
R.F.U.
1 k
Ω
1 k
Ω
10 k
Ω
V
DD
V
DD
3 to 10 k
Ω
V
DD
V
DD
V
DD
V
DD
1 to 10 k
Ω
V
DD
Caution The constants described in the circuit connection example are reference values. If you
perform flash programming aiming at mass production, thoroughly evaluate whether the
specifications of the target device are satisfied.
Notes 1.
The RESET pin is used to download the monitor program at debugger startup or to implement
forced reset. Therefore, a pin that alternately functions as the RESET pin cannot be used. For
reset pin connection, refer to
QB-MINI2 User’s Manual (U18371E)
.
2.
This is the pin connection when the X1 and X2 pins are not used in the target system. When using
the X1 and X2 pins, refer to
17.1.2 Connection of X1 and X2 pins
.
3.
No problem will occur if the dashed line portions are connected.
4.
This pin is connected to enhance the accuracy of time measurement between run and break during
debugging. Debugging is possible even if this pin is left open, but measurement error occurs in
several ms units.
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