UPD753012GC NEC, UPD753012GC Datasheet - Page 22

• Manufacturer Part Number: UPD753012GC
• Description: 4-BIT SINGLE-CHIP MICROCONTROLLER
• Manufacturer: NEC

6.2 Clock Generator
control register (SCC).
Note Instruction execution
Remarks 1.
22
Operation of the clock generator is determined by the processor clock control register (PCC) and system clock
The two clocks, the main system clock and subsystem clock, are available.
The instruction excution time can be altered.
• 0.95 s, 1.91 s, 3.81 s, 15.3 s (main system clock : at 4.19 MHz operation)
• 0.67 s, 1.33 s, 2.67 s, 10.7 s (main system clock : at 6.0 MHz operation)
• 122 s (subsystem clock : at 32.768 kHz operation)
2.
3.
4.
5.
6.
V
V
DD
DD
STOP
HALT
f
f
PCC: Processor Clock Control Register
SCC: System Clock Control Register
One clock cycle (t
4
X
XT
= Main system clock frequency
= CPU clock
Note
Note
= Subsystem clock frequency
PCC2,
WM.3
SCC3
SCC0
PCC0
PCC1
PCC2
PCC3
PCC3
Clear
SCC
PCC
XT1
XT2
X1
X2
Subsystem
clock oscillator
Main system
clock oscillator
Figure 6-1. Clock Generator Block Diagram
CY
Oscillation
stop
) of
STOP F/F
Q
f
f
S
R
XT
X
equal to one machine cycle of the instruction.
LCD controller/driver
Watch timer
1/2 1/4 1/16
Selector
1/1~1/4096
Divider
HALT F/F
S
R
Selector
Q
· Basic interval timer (BT)
· Timer/event counter
· Serial interface
· Watch timer
· LCD controller/driver
· INT0 noise eliminator
· Clock output circuit
Wait release signal from BT
RESET signal
Standby release signal from
interrupt control circuit
PD753012, 753016, 753017
Divider
1/4
· CPU
· INT0 noise eliminator
· Clock output circuit