UPD75068GBA データシートの表示（PDF） - NEC => Renesas Technology

部品番号

コンポーネント説明

メーカー

UPD75068GBA

4-BIT SINGLE-CHIP MICROCOMPUTER

NEC => Renesas Technology 

µPD75064, 75066, 75068, 75064(A), 75066(A), 75068(A)

5.2 Clock Generator

The clock generator operates according to the statuses of the processor clock control register (PCC) and

the system clock control register (SCC). Two types of clock are provided: main system clock and subsystem

clock, and the instruction execution time can be changed.

• 0.95 µs / 1.91 µs / 15.3 µs (operated with main system clock at 4.19 MHz)

• 122 µs (operated with subsystem clock at 32.768 kHz)

Figure 5-1. Clock Generator Block Diagram

XT1

Subsystem

fXT

clock generator

XT2

X1

Main system fX

clock generator

X2

Watch timer

 • Basic interval timer (BT)

 • Timer/event counter







•

•

Serial interface

Watch timer

 • A /D converter

 (successive approximation type)

 • INT0 noise eliminator

 • Clock output circuit

1/2 1/16

1/2 to 1/4096

Frequency divider

WM.3

SCC

SCC3

SCC0

PCC

PCC0

PCC1

4

PCC2

HALT Note

PCC3

STOP Note

PCC2, PCC3

clear signal

Oscillator

disable

signal

STOP F/F

QS

R

Selec-

tor

Selec-

tor

Frequency

divider

1/4

Φ

 • CPU

 • INT0 noise

 eliminator

 • Clock output

 circuit

HALT F/F

S

RQ

Wait release signal from BT

RESET signal

Standby release signal from

interrupt control circuit

Note Instruction execution

Remarks

1. fX = Main system clock frequency

2. fXT = Subsystem clock frequency

3. Φ = CPU clock

4. PCC: Processor clock control register

5. SCC: System clock control register

6. One clock cycle (tCY) at Φ is equal to one machine cycle of an instruction.

For tCY, refer to AC Characteristics in 10. ELECTRICAL SPECIFICATIONS.

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