UPD78F9502MA-CAC-A NEC, UPD78F9502MA-CAC-A Datasheet - Page 66

• 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

5.5
oscillators.
OPTION BYTE.
(1) High-speed internal oscillator
66
A clock (f
The system clock oscillator is selected by the option byte. For details of the option byte, refer to CHAPTER 13
Note Operation stop time is 277 s (MIN.), 544 s (TYP.), and 1.075 ms (MAX.).
Remark When the high-speed internal oscillation is used, the clock accuracy is 5%.
When the high-speed internal oscillation is selected by the option byte, the following is possible.
Figures 5-6 and 5-7 show the timing chart and status transition diagram of the default start by the high-speed
internal oscillation.
High-speed internal oscillator:
External clock input circuit:
Operation of CPU Clock Generator
Shortening of start time
If the high-speed internal oscillator is selected as the oscillator, the CPU can be started without having to wait
for the oscillation stabilization time of the system clock. Therefore, the start time can be shortened.
Improvement of expandability
If the high-speed internal oscillator is selected as the oscillator, the EXCLK pin can be used as I/O port pins.
For details, refer to CHAPTER 4 PORT FUNCTIONS.
System clock
Internal reset
CPU
CPU clock
) is supplied to the CPU from the system clock (f
RESET
Figure 5-6. Timing Chart of Default Start by High-Speed Internal Oscillation
V
DD
H
(a)
System clock is selected.
Internally oscillates a clock of 8 MHz (TYP.).
Supplies a clock of 1 MHz to 10 MHz to EXCLK pin.
(Operation stops
CHAPTER 5 CLOCK GENERATORS
Option byte is read.
Preliminary User’s Manual U18681EJ1V0UD
Note
)
(b)
X
) oscillated by one of the following three types of
High-speed internal oscillation clock
PCC = 02H, PPCC = 02H