upd78f0103hmca1-5a4-a Renesas Electronics Corporation., upd78f0103hmca1-5a4-a Datasheet - Page 343

• Manufacturer Part Number: upd78f0103hmca1-5a4-a
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

(1) Signal collision
(2) Malfunction of other device
If the dedicated flash programmer (output) is connected to a pin (input) of a serial interface connected to another
device (output), signal collision takes place. To avoid this collision, either isolate the connection with the other
device, or make the other device go into an output high-impedance state.
If the dedicated flash programmer (output or input) is connected to a pin (input or output) of a serial interface
connected to another device (input), a signal may be output to the other device, causing the device to malfunction.
To avoid this malfunction, either isolate the connection with the other device.
78K0/KB1+
78K0/KB1+
78K0/KB1+
Input pin
Pin
Pin
Figure 21-11. Signal Collision (Input Pin of Serial Interface)
If the signal output by the 78K0/KB1+ in the flash memory programming
mode affects the other device, isolate the signal of the other device.
If the signal output by the dedicated flash programmer in the flash memory
programming mode affects the other device, isolate the signal of the other
device.
In the flash memory programming mode, the signal output by the device
collides with the signal sent from the dedicated flash programmer.
Therefore, isolate the signal of the other device.
Figure 21-12. Malfunction of Other Device
Signal collision
CHAPTER 21 FLASH MEMORY
User’s Manual U16846EJ3V0UD
Dedicated flash programmer
connection pin
Dedicated flash programmer
connection pin
Dedicated flash programmer
connection pin
Other device
Other device
Other device
Output pin
Input pin
Input pin
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