UPD78F0537DGA(T)-9EV-A NEC, UPD78F0537DGA(T)-9EV-A Datasheet - Page 141

• Manufacturer Part Number: UPD78F0537DGA(T)-9EV-A
• Description: 8BIT MCU, 128K FLASH, 7KB RAM, SMD
• Manufacturer: NEC

Specifications of UPD78F0537DGA(T)-9EV-A

• Controller Family/series: UPD78
• No. Of I/o's: 55
• Ram Memory Size: 7KB
• Cpu Speed: 20MHz
• No. Of Timers: 8
• No. Of Pwm: RoHS Compliant
• Core Size: 8bit
• Program Memory Size: 128KB
• Oscillator Type: External, Internal

6.2 Configuration of Clock Generator
(3) Internal low-speed oscillation clock (clock for watchdog timer)
Remark f
The clock generator includes the following hardware.
Control registers
Oscillators
• Internal low-speed oscillator
This circuit oscillates a clock of f
clock always starts operating.
Oscillation can be stopped by using the internal oscillation mode register (RCM) when “internal low-speed
oscillator can be stopped by software” is set by option byte.
The internal low-speed oscillation clock cannot be used as the CPU clock. The following hardware operates
with the internal low-speed oscillation clock.
• Watchdog timer
• TMH1 (when f
RL
Item
:
Internal low-speed oscillation clock frequency
RL
, f
RL
/2
Clock operation mode select register (OSCCTL)
Processor clock control register (PCC)
Internal oscillation mode register (RCM)
Main OSC control register (MOC)
Main clock mode register (MCM)
Oscillation stabilization time counter status register (OSTC)
Oscillation stabilization time select register (OSTS)
X1 oscillator
XT1 oscillator
Internal high-speed oscillator
Internal low-speed oscillator
7
, or f
Table 6-1. Configuration of Clock Generator
RL
/2
CHAPTER 6 CLOCK GENERATOR
RL
9
is selected)
= 240 kHz (TYP.). After a reset release, the internal low-speed oscillation
User’s Manual U17260EJ6V0UD
Configuration
141