upd78f9211grt2-jjg-a ETC-unknow, upd78f9211grt2-jjg-a Datasheet - Page 216

• Manufacturer Part Number: upd78f9211grt2-jjg-a
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: ETC-unknow

16.6
the target system. First provide a function that selects the normal operation mode or flash memory programming
mode on the board.
the same status as immediately after reset. Therefore, if the external device does not recognize the state immediately
after reset, the pins must be processed as described below.
16.6.1 X1 and X2 pins
pins are connected to an external device, a signal conflict occurs. To prevent the conflict of signals, isolate the
connection with the external device.
it is difficult to isolate the resonator, while a crystal or ceramic resonator is selected as the system clock.
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To write the flash memory on-board, connectors that connect the dedicated flash programmer must be provided on
When the flash memory programming mode is set, all the pins not used for programming the flash memory are in
The state of the pins in the self programming mode is the same as that in the HALT mode.
The X1 and X2 pins are used as the serial interface of flash memory programming. Therefore, if the X1 and X2
Perform the following processing (1) and (2) when on-board writing is performed with the resonator mounted, when
(1) Mount the minimum-possible test pads between the device and the resonator, and connect the flash
(2) Set the oscillation frequency of the communication clock for writing using the GUI software of the dedicated
Processing of Pins on Board
programmer via the test pad. Keep the wiring as short as possible (refer to Figure 16-6 and Table 16-4).
flash programmer. Research the series/parallel resonant and antiresonant frequencies of the resonator used,
and set the oscillation frequency so that it is outside the range of the resonant frequency ±10% (refer to Figure
16-7 and Table 16-5).
High-speed internal oscillation clock
External clock
Crystal/ceramic oscillation
clock
Table 16-4. Clock to Be Used and Mounting of Test Pads
Figure 16-6. Example of Mounting Test Pads
Clock to Be Used
CHAPTER 16 FLASH MEMORY
Before resonator is mounted
After resonator is mounted
User’s Manual U16994EJ3V0UD
V
SS
X1
Test pad
X2
Not required
Required
Mounting of Test Pads