upd78f0730 Renesas Electronics Corporation., upd78f0730 Datasheet - Page 459

• Manufacturer Part Number: upd78f0730
• Description: 8-bit Single-chip Microcontroller
• Manufacturer: Renesas Electronics Corporation.

(1) Signal collision
(2) Malfunction of other device
If the dedicated flash memory 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 memory 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, isolate the connection with the other device.
µ
µ
µ
PD78F0730
PD78F0730
PD78F0730
Input pin
Pin
Pin
Figure 19-9. Signal Collision (Input Pin of Serial Interface)
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.
If the signal output by the PD78F0730 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.
Figure 19-10. Malfunction of Other Device
Signal collision
Preliminary User’s Manual U19014EJ1V0UD
CHAPTER 19 FLASH MEMORY
µ
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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