HD6433937 Datasheet, PDF (128/521 Pages) Hitachi Semiconductor – Hardware Manual

4. Time for direct transition from subactive mode to active (medium-speed) mode
A direct transition from subactive mode to active (medium-speed) mode is performed by
executing a SLEEP instruction in subactive mode while bit SSBY is set to 1 and bit LSON is
cleared to 0 in SYSCR1, bits MSON and DTON are both set to 1 in SYSCR2, and bit TMA3 is set
to 1 in TMA. The time from execution of the SLEEP instruction to the end of interrupt exception
handling (the direct transition time) is given by equation (4) below.
Direct transition time = { (Number of SLEEP instruction execution states) + (number of internal
processing states) } × (t_subcyc before transition) + { (wait time set in STS2
to STS0) + (number of interrupt exception handling execution states) } ×
(t_cyc after transition)
........................ (4)
Example: Direct transition time = (2 + 1) × 8t_w + (8192 + 14) × 16t_osc= 24t_w + 131296t_osc (when
øw/8 or ø8 is selected as the CPU operating clock, and wait time = 8192 states)
Notation:
t_osc:
t_w:
t_cyc:
t_subcyc:
OSC clock cycle time
Watch clock cycle time
System clock (ø) cycle time
Subclock (ø_SUB) cycle time
5.8.3 Notes on External Input Signal Changes before/after Direct Transition
1. Direct transition from active (high-speed) mode to subactive mode
Since the mode transition is performed via watch mode, see 5.3.5, Notes on External Input
Signal Changes before/after Standby Mode.
2. Direct transition from active (medium-speed) mode to subactive mode
Since the mode transition is performed via watch mode, see 5.3.5, Notes on External Input
Signal Changes before/after Standby Mode.
3. Direct transition from subactive mode to active (high-speed) mode
Since the mode transition is performed via watch mode, see 5.3.5, Notes on External Input
Signal Changes before/after Standby Mode.
4. Direct transition from subactive mode to active (medium-speed) mode
Since the mode transition is performed via watch mode, see 5.3.5, Notes on External Input
Signal Changes before/after Standby Mode.
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