NEC mPD780024AS Series, Preliminary User'S Manual

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CHAPTER 16 STANDBY FUNCTION
Preliminary User’s Manual U16035EJ1V0UM
16.2 Operations of Standby Function
16.2.1 HALT mode
(1) HALT mode setting and operating status
The HALT mode is set by executing the HALT instruction. It can be set with the main system clock or the
subsystem clock.
The operating status in the HALT mode is described below.
Table 16-1. HALT Mode Operating Status
HALT Mode During HALT Instruction Execution During HALT Instruction Execution
Setting Using Main System Clock Using Subsystem Clock
Without Subsystem With Subsystem With Main System With Main System
Item Clock
Note 1
Clock
Note 2
Clock Oscillation Clock Oscillation Stopped
Clock generator Both main system clock and subsystem clock can be oscillated. Clock supply to CPU stops.
CPU Operation stops.
Port (output latch) Status before HALT mode setting is held.
16-bit timer/event Operable Operation stops.
counter
8-bit timer/event Operable Operable when TI50,
counter TI51 are selected as
count clock.
Watch timer Operable when f
X
/2
7
is Operable Operable when f
XT
is
selected as count clock selected as count clock.
Watchdog timer Operable Operation stops.
A/D converter Operation stops.
Serial interface Operable Operable during
external SCK.
External interrupt Operable
Notes 1. Including case when external clock is not supplied.
2. Including case when external clock is supplied.