UPD78F9234MC-5A4-A Datasheet, PDF (333/419 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

CHAPTER 20 ON-CHIP DEBUG FUNCTION
Notes 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.
5. The INTP3 pin is used for communication between QB-MINI2 and the target device during
debugging. When debugging is performed with QB-MINI2, therefore, the INTP3 pin and its
alternate-function pin cannot be used. For INTP3 pin connection, refer to 20.1.1 Connection of
INTP3 pin.
Pins for communication depend on whether the monitor program has been written or not. (refer to Table 20-1)
X1 and X2 pins can be used as I/O port pins or the pins for oscillation, after the monitor program has been written.
Table 20-1. Pins for communication with QB-MINI2
Before writing the monitor program
X1, X2, RESET, INTP3, VDD, VSS
After writing the monitor program
RESET, INTP3, VDD, VSS
20.1.1 Connection of INTP3 pin
The INTP3 pin is used only for communication between QB-MINI2 and the target device during debugging.
Design circuits appropriately according to the relevant case among the cases shown below.
(1) INTP3 pin is not used in target system (as is illustrated in Figure 20-1. Recommended Circuit
Connection)
→ See Figure 20-2.
(2) QB-MINI2 is used only for programming, not for debugging
→ See Figure 20-3.
(3) QB-MINI2 is used for debugging and debugging of the INTP3 pin is performed only with a real machine
→ See Figure 20-4.
Figure 20-2. Circuit Connection for the Case Where INTP3 Pin Is Not Used in Target System
VDD
Target connector
12
INTP
1 kΩ
Target device
INTP3
Figure 20-3. Circuit Connection for the Case Where QB-MINI2 Is Used Only for Programming
Target connector
Target device
12
INTP
INTP3
User’s Manual U17446EJ5V0UD
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