NEC 78K0/KB1+, Preliminary User'S Manual

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CHAPTER 15 STANDBY FUNCTION
Preliminary User’s Manual U16846EJ1V0UD
297
15.2 Standby Function Operation
15.2.1 HALT mode
(1) HALT mode
The HALT mode is set by executing the HALT instruction. HALT mode can be set when the CPU clock before
the setting was the high-speed system clock or Ring-OSC clock.
The operating statuses in the HALT mode are shown below.
Table 15-2. Operating Statuses in HALT Mode
When HALT Instruction Is Executed While
CPU Is Operating Using High-Speed
System Clock
When HALT Instruction Is Executed While
CPU Is Operating Using Ring-OSC Clock
HALT Mode Setting
Item
Ring-OSC Oscillation
Continues
Ring-OSC Oscillation
Stopped
Note 1
High-Speed System
Clock Oscillation
Continues
High-Speed System
Clock Oscillation
Stopped
System clock Clock supply to the CPU is stopped
CPU Operation stopped
Port (output latch) Holds the status before HALT mode was set
16-bit timer/event counter 00 Operable Operation not guaranteed
8-bit timer/event counter 50 Operable Operation not guaranteed when count
clock other than TI50 is selected
8-bit timer H0 Operable Operation not guaranteed when count
clock other than TM50 output is selected
during 8-bit timer/event counter 50
operation
8-bit timer H1 Operable Operation not guaranteed when count
clock other than f
R
/2
7
is selected
Ring-OSC cannot be
stopped
Note 2
Operable
−
Operable Watchdog
timer
Ring-OSC can be
stopped
Note 2
Operation stopped
A/D converter Operable Operation not guaranteed
UART0
Note 3
Operable
UART6 Operable
Operation not guaranteed when serial
clock other than TM50 output is selected
during 8-bit timer/event counter 50
operation
Serial interface
CSI10 Operable Operation not guaranteed when serial
clock other than external SCK10 is
selected
Clock monitor Operable Operation stopped Operable Operation stopped
Power-on-clear function Operable
Low-voltage detection function Operable
External interrupt Operable
Notes 1. When “Stopped by software” is selected for Ring-OSC by the option byte and Ring-OSC is stopped by
software (for the option byte, see CHAPTER 20 OPTION BYTE).
2. “Ring-OSC cannot be stopped” or “Ring-OSC can be stopped by software” can be selected by the option
byte.
3.
µ
PD78F0102H and 78F0103H only.