Idle Mode - NEC Renesas V850/SC1 User Manual

4.4.3 IDLE mode

(1) Settings and operating states
This mode stops the entire system except the watch timer by stopping the on-chip main clock supply while the
clock oscillator is still operating. Supply to the subclock continues. When this mode is canceled, there is no
need for the oscillator to wait for the oscillation stabilization time, so normal operation can be resumed quickly.
When in IDLE mode, program execution is stopped and the contents of all registers and internal RAM are
retained as they were just before IDLE mode was set. In addition, on-chip peripheral functions are stopped
(except for peripheral functions that are operating with the subclock). External bus hold requests (HLDRQ) are
not acknowledged.
When the IDLE bit of the power save control register (PSC) is set (1), the system switches to IDLE mode.
The operating statuses in IDLE mode are listed in Table 4-2.
(2) Cancellation of IDLE mode
IDLE mode can be canceled by a non-maskable interrupt, an unmasked maskable interrupt request output from
an operable on-chip peripheral I/O, or RESET input.
IDLE Mode Settings
Item
CPU
ROM correction
Clock generator
16-bit timer (TM0)
16-bit timer (TM1)
16-bit timer (TM5)
16-bit timer (TM6)
16-bit timer (TM7 to TM12)
Watch timer
Watchdog timer
Serial CSI0,
interfaces CSI2 to CSI6
2 2
I C0, I C1
UART0 to
UART3
IEBus (V850/SC2 only)
Note
FCAN1, FCAN2
(V850/SC3 only)
A/D converter
DMA0 to DMA5
Port function
Note Available only for the µ PD703089Y, 70F3089Y.
CHAPTER 4 CLOCK GENERATION FUNCTION
Table 4-2. Operating Statuses in IDLE Mode (1/2)
When Subclock Exists
Stopped
Stopped
Both main clock and subclock oscillating
Clock supply to CPU and on-chip peripheral functions is stopped
Operates when INTWTNI is selected as the
count clock (f is selected for watch timer)
XT
Stopped
Operates when f is selected for the count
XT
clock
Stopped
Stopped
Operating
Stopped
Operates when an external clock is selected as the serial clock
Stopped
Operates only for transmission when an external clock is selected as the baud rate clock
Stopped
Stopped
Stopped
Stopped
Held
User's Manual U15109EJ3V0UD
When Subclock Does Not Exist
Stopped
Stopped
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