
CHAPTER 5 CLOCK GENERATOR
User’s Manual U19780EJ2V0UD
158
5.6.6 CPU clock status transition diagram
Figures 5-15 and 5-16 show the CPU clock status transition diagrams of this product.
Figure 5-15. CPU Clock Status Transition Diagram
(When 1.59 V POC Mode Is Set (Option Byte: POCMODE = 0), 78K0/KB2-A)
Power ON
Reset release
V
DD
≥
1.8 V (MIN.)
CPU: Operating
with X1 oscillation or
EXCLK input
CPU: X1
oscillation/EXCLK
input
→
STOP
CPU: X1
oscillation/EXCLK
input
→
HALT
(B)
(A)
(C)
(E)
(D)
(F)
(G)
Internal low-speed oscillation: Woken up
Internal high-speed oscillation: Woken up
X1 oscillation/EXCLK input: Stops (I/O port mode)
V
DD
< 1.59 V (TYP.)
V
DD
≥
1.59 V (TYP.)
Internal low-speed oscillation: Operating
Internal high-speed oscillation: Operating
X1 oscillation/EXCLK input: Stops (I/O port mode)
CPU: Operating
with internal high-
speed oscillation
Internal low-speed oscillation: Operable
Internal high-speed oscillation: Operating
X1 oscillation/EXCLK input:
Selectable by CPU
Internal low-speed oscillation: Operable
Internal high-speed oscillation:
Selectable by CPU
X1 oscillation/EXCLK input: Operating
Internal low-speed oscillation:
Operable
Internal high-speed oscillation:
Stops
X1 oscillation/EXCLK input: Stops
Internal low-speed oscillation:
Operable
Internal high-speed oscillation:
Operating
X1 oscillation/EXCLK input: Operable
Internal low-speed oscillation:
Operable
Internal high-speed oscillation:
Stops
X1 oscillation/EXCLK input: Stops
Internal low-speed oscillation:
Operable
Internal high-speed oscillation:
Operable
X1 oscillation/EXCLK input: Operating
CPU: Internal high-
speed oscillation
→
STOP
CPU: Internal high-
speed oscillation
→
HALT
Remark
In the 2.7 V/1.59 V POC mode (option byte: POCMODE = 1), the CPU clock status changes to (A) in the
above figure when the supply voltage exceeds 2.7 V (TYP.), and to (B) after reset processing (11 to
45
μ
s).