UPD78F9222MC(T)-5A4-A NEC, UPD78F9222MC(T)-5A4-A Datasheet - Page 74

• Manufacturer Part Number: UPD78F9222MC(T)-5A4-A
• Description: 8BIT MCU, 4K FLASH, 256B RAM, 78F9222
• Manufacturer: NEC

Specifications of UPD78F9222MC(T)-5A4-A

• Controller Family/series: UPD78
• No. Of I/o's: 17
• Ram Memory Size: 256Byte
• Cpu Speed: 10MHz
• No. Of Timers: 4
• No. Of: RoHS Compliant
• Core Size: 8bit
• Program Memory Size: 4KB
• Oscillator Type: External, Internal

5.4
5.4.1
used as I/O port pins.
PORT FUNCTIONS.
5.4.2
pins.
used as crystal or ceramic resonator connection pins.
PORT FUNCTIONS.
74
The following three types of system clock oscillators are available.
• High-speed internal oscillator:
• Crystal/ceramic oscillator:
• External clock input circuit:
The 78K0S/KA1+ includes a high-speed internal oscillator (8 MHz (TYP.)).
If the high-speed internal oscillation is selected by the option byte as the clock source, the X1 and X2 pins can be
For details of the option byte, refer to CHAPTER 17 OPTION BYTE. For details of I/O ports, refer to CHAPTER 4
The crystal/ceramic oscillator oscillates using a crystal or ceramic resonator connected between the X1 and X2
If the crystal/ceramic oscillator is selected by the option byte as the system clock source, the X1 and X2 pins are
For details of the option byte, refer to CHAPTER 17 OPTION BYTE. For details of I/O ports, refer to CHAPTER 4
Figure 5-6 shows the external circuit of the crystal/ceramic oscillator.
Caution When using the crystal/ceramic oscillator, wire as follows in the area enclosed by the broken
System Clock Oscillators
High-speed internal oscillator
Crystal/ceramic oscillator
lines in Figure 5-6 to avoid an adverse effect from wiring capacitance.
• Keep the wiring length as short as possible.
• Do not cross the wiring with the other signal lines. Do not route the wiring near a signal line
• Always make the ground point of the oscillator capacitor the same potential as V
• Do not fetch signals from the oscillator.
through which a high fluctuating current flows.
ground the capacitor to a ground pattern through which a high current flows.
Figure 5-6. External Circuit of Crystal/Ceramic Oscillator
Internally oscillates a clock of 8 MHz (TYP.).
Oscillates a clock of 2 to 10 MHz.
Supplies a clock of 2 to 10 MHz to the X1 pin.
CHAPTER 5 CLOCK GENERATORS
User’s Manual U16898EJ5V0UD
Crystal resonator
or ceramic resonator
V
X1
X2
SS
SS
. Do not