H838024 datasheet(182/697 Pages) RENESAS

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Section 5 Power-Down Modes

Rev. 7.00 Mar 10, 2005 page 140 of 652

REJ09B0042-0700

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) } • (tsubcyc before transition) + { (wait time set in

STS2 to STS0) + (number of interrupt exception handling execution

states) } • (tcyc after transition)

........................ (4)

Example: Direct transition time = (2 + 1) • 8tw + (8192 + 14) • 16tosc = 24tw + 131296tosc

(when

φw/8 or φ/8 is selected as the CPU operating clock, and wait time = 8192 states)

[Legend]

tosc:

OSC clock cycle time

tw:

Watch clock cycle time

tcyc:

System clock (

φ) cycle time

tsubcyc: Subclock (

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 section 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 section 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 section 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 section 5.3.5, Notes on External

Input Signal Changes before/after Standby Mode.

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