CHAPTER 18 STANDBY FUNCTION
Preliminary User’s Manual U16315EJ1V0UD
350
(b) Release by RESET input
When the RESET signal is input, HALT mode is released, and then, as in the case with a normal reset
operation, the program is executed after branching to the reset vector address.
Figure 18-5. HALT Mode Release by RESET Input
(1) When X1 input clock is used as CPU clock
HALT
instruction
RESET signal
X1 input clock
Operating mode
HALT mode
Reset
period
Operation
stopped
Operating mode
Oscillates
Oscillation
stopped
Oscillates
CPU clock
(X1 input clock)
Oscillation stabilization time
(2
11
/f
X
to 2
16
/f
X
)
(Ring-OSC clock)
(17/f
R
)
(2) When Ring-OSC clock or subsystem clock is used as CPU clock
HALT
instruction
RESET signal
Ring-OSC clock
or
subsystem clock
Operating mode
HALT mode
Reset
period
Operation
stopped
Operating mode
Oscillates
Oscillation
stopped
Oscillates
CPU clock
(Ring-OSC clock)
(17/f
R
)
Ring-OSC clock
or
subsystem clock
Remarks 1.
f
X
: X1 input clock oscillation frequency
2.
f
R
: Ring-OSC clock oscillation frequency
Table 18-3. Operation After HALT Mode Release
Release Source
MK
××
PR
××
IE
ISP
Operation
0
0
0
×
Next address
instruction execution
0
0
1
×
Interrupt servicing
execution
0
1
0
1
0
1
×
0
Next address
instruction execution
0
1
1
1
Interrupt servicing
execution
Maskable interrupt
request
1
×
×
×
HALT mode held
RESET input
−
−
×
×
Reset processing
×
: Don’t care