UPD78F9502MA-CAC-A NEC, UPD78F9502MA-CAC-A Datasheet - Page 134

• Manufacturer Part Number: UPD78F9502MA-CAC-A
• Description: 8BIT MCU, 4K FLASH, 128B RAM, SMD
• Manufacturer: NEC

Specifications of UPD78F9502MA-CAC-A

• Controller Family/series: UPD78F
• No. Of I/o's: 8
• Ram Memory Size: 128Byte
• Cpu Speed: 10MHz
• No. Of Timers: 2
• No. Of Pwm: RoHS Compliant
• Core Size: 8bit
• Program Memory Size: 4KB
• Oscillator Type: External, Internal

13.2 Format of Option Byte
134
Format of option bytes is shown below.
Remark When used as RESET pin, the pin can be left open by setting ENPU34 to "1" while the pin is not in
Caution Because the option byte is referenced after reset release, if a low level is input to the RESET
Caution Because the EXCLK pin is also used as the P23 pin, the condition under which the EXCLK
Remark
Address: 0080H
OSCSEL1
ENPU34
RMCE
7
1
1
0
1
0
0
0
1
use.
pin before the option byte is referenced, then the reset state is not released.
When used as an input-only port (P34), the setting of the on-chip pull-up resistor can be done
by PU34 on PU3 register.
pin can be used differ depending on the selected system clock source.
(1) External clock input is selected
(2) High-speed internal oscillation clock is selected
: don’t care
Because the pin is used as an external clock input pin, P23 cannot be used as an I/O port
pin.
P23 pin can be used as an I/O port pin.
OSCSEL0
On-chip pull-up resistor on RESET pin is not selected.
RESET pin is used as is.
RESET pin is used as input port pin (P34).
On-chip pull-up resistor on RESET pin is selected.
0
1
6
1
Setting prohibited
External clock input
High-speed internal oscillation clock
Figure 13-2. Format of Option Byte (1/2)
5
1
Preliminary User’s Manual U18681EJ1V0UD
Selection of on-chip pull-up resistor on RESET pin
CHAPTER 13 OPTION BYTE
ENPU34
4
Control of RESET pin
Selection of system clock source
RMCE
3
OSCSEL1
2
OSCSEL0
1
LIOCP
0