205
CHAPTER 15 STANDBY FUNCTION
User’s Manual U15104EJ2V0UD
15.2 Operations of Standby Function
15.2.1 HALT mode
(1) HALT mode set and operating status
The HALT mode is set by executing the HALT instruction.
The operating status in the HALT mode is described below.
Table 15-1. HALT Mode Operating Status
Item
Status
Clock generator
Can oscillate system clock. Stops clock supply to CPU.
CPU
Stops operating.
Port
Holds status before HALT mode is set.
8-bit timer/event counter
Holds operation before HALT mode is set and can operate.
Basic timer
Watchdog timer
Buzzer output controller
A/D converter
Retains operation performed when HALT mode is set.
However, comparison cannot be performed correctly in A/D conversion operation mode.
In power-fail comparison mode, operation is as follows depending on setting of bit 5
(PFHRM3) of power-fail comparison mode register 3 (PFM3):
• PFHRM3 = 0: Comparison cannot be performed normally.
• PFHRM3: Power-fail comparison operation can be performed.
Serial interface
Retains operation performed when HALT mode is set and can operate.
(SIO30 to SIO32)
External interrupt
Hold operation before HALT mode is set and can operate.
PLL frequency synthesizer
Frequency counter
Retains operation performed before HALT mode is set.
However, operation is not performed correctly though it is continued.
Power-on clear circuit
Reset when voltage of less than 3.5 V is detected.
Содержание mPD178053
Страница 2: ...2 User s Manual U15104EJ2V0UD MEMO ...