tmp88f846ug TOSHIBA Semiconductor CORPORATION, tmp88f846ug Datasheet - Page 19

• Manufacturer Part Number: tmp88f846ug
• Description: 8 Bit Microcontroller
• Manufacturer: TOSHIBA Semiconductor CORPORATION

2.1.4 System Clock Control Circuit
2.1.4.1 On-Chip Oscillator
2.1.4.2 Timing Generator
circuit.
The System Clock Control Circuit consists of an On-Chip Oscillator, timing generator, and standby control
plied to the CPU core and peripheral hardware units.
past.
the CPU core and peripheral hardware units. The Timing Generator has the following functions:
(1)
The On-Chip Oscillator the fundamental clock which serves as the reference for the system clocks sup-
The frequency clock (frequency fc) be fixed at 20MHz, and it is changed by temperature or many years
Measurement of the oscillation frequency
Note: Although no hardware functions are provided that allow the fundamental clock to be monitored directly
The Timing Generator generates various system clocks from the fundamental clock that are supplied to
1. Generate a divider output (
2. Generate the source clock for the time base timer
3. Generate the source clock for the watchdog timer
4. Generate the internal source clock for the timer counter
5. Generate a warm-up clock when exiting STOP mode
Configuration of the Timing Generator
The Timing Generator a 3-stage prescaler, 21-stage dividers, and a machine cycle counter.
When reset and when entering/exiting STOP mode, the prescaler and dividers are cleared to 0.
High-frequency
clock oscillator
from the outside, the oscillation frequency can be measured by forwarding the pulse of a fixed fre-
quency (e.g., clock output) to a port and monitoring it in a program while interrupts and the watchdog
timer are disabled. For systems that require adjusting the oscillation frequency, an adjustment program
must be created beforehand.
Oscillator
On-Chip
circuit
Figure 2-2 System Clock Control Circuit
Timing generator control register
fc
Timing generator
System clocks
DVO
TBTCR
Page 9
) pulse
00036H
00038H
SYSCR1
System control register
Standby control circuit
00039H
SYSCR2
TMP88F846UG