UPD78F9222MC(T)-5A4-A NEC, UPD78F9222MC(T)-5A4-A Datasheet - Page 263

• 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

17.2 Format of Option Byte
Format of option bytes is shown below.
Caution The setting of this option is valid only when the crystal/ceramic oscillation clock is selected
Caution Because the option byte is referenced after reset release, if a low level is input to the RESET
Caution Because the X1 and X2 pins are also used as the P121 and P122 pins, the conditions under
Remark
Address: 0080H
DEFOSTS1
OSCSEL1
RMCE
7
1
1
0
0
0
1
0
0
1
1
as the system clock source. No wait time elapses if the high-speed internal oscillation clock
or external clock input is selected as the system clock source.
pin before the option byte is referenced, then the reset state is not released.
Also, when setting 0 to RMCE, connect the pull-up resistor.
which the X1 and X2 pins can be used differ depending on the selected system clock source.
(1) Crystal/ceramic oscillation clock is selected
(2) External clock input is selected
(3) High-speed internal oscillation clock is selected
× : don’t care
DEFOSTS1
DEFOSTS0
The X1 and X2 pins cannot be used as I/O port pins because they are used as clock input
pins.
Because the X1 pin is used as an external clock input pin, P121 cannot be used as an I/O
port pin.
P121 and P122 can be used as I/O port pins.
OSCSEL0
RESET pin is used as is.
RESET pin is used as input port pin (P34).
0
1
×
6
0
1
0
1
DEFOSTS0
2
2
2
2
Crystal/ceramic oscillation clock
External clock input
High-speed internal oscillation clock
10
12
15
17
Figure 17-2. Format of Option Byte (1/2)
/fx (102.4
/fx (409.6
/fx (3.27 ms)
/fx (13.1 ms)
5
Oscillation stabilization time on power application or after reset release
CHAPTER 17 OPTION BYTE
User’s Manual U16898EJ5V0UD
µ
µ
s)
s)
4
1
Control of RESET pin
Selection of system clock source
RMCE
3
OSCSEL1
2
OSCSEL0
1
LIOCP
0
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