Datasheet

V850ES/JG3 CHAPTER 21 STANDBY FUNCTION
R01UH0015EJ0300 Rev.3.00 Page 680 of 870
Sep 30, 2010
21.4 IDLE1 Mode
21.4.1 Setting and operation status
The IDLE1 mode is set by clearing the PSMR.PSM1 and PSMR.PSM0 bits to 00 and setting the PSC.STP bit to 1 in
the normal operation mode.
In the IDLE1 mode, the clock oscillator, PLL, and flash memory continue operating but clock supply to the CPU and
other on-chip peripheral functions stops.
As a result, program execution stops and the contents of the internal RAM before the IDLE1 mode was set are retained.
The CPU and other on-chip peripheral functions stop operating. However, the on-chip peripheral functions that can
operate with the subclock or an external clock continue operating.
Table 21-5 shows the operating status in the IDLE1 mode.
The IDLE1 mode can reduce the power consumption more than the HALT mode because it stops the operation of the
on-chip peripheral functions. The main clock oscillator does not stop, so the normal operation mode can be restored
without waiting for the oscillation stabilization time after the IDLE1 mode has been released, in the same manner as when
the HALT mode is released.
Cautions 1. Insert five or more NOP instructions after the instruction that stores data in the PSC register to
set the IDLE1 mode.
2. If the IDLE1 mode is set while an unmasked interrupt request signal is being held pending, the
IDLE1 mode is released immediately by the pending interrupt request.
21.4.2 Releasing IDLE1 mode
The IDLE1 mode is released by a non-maskable interrupt request signal (NMI pin input, INTWDT2 signal), unmasked
external interrupt request signal (INTP0 to INTP7 pin input), unmasked internal interrupt request signal from a peripheral
function operable in the IDLE1 mode, or reset signal (reset by RESET pin input, WDT2RES signal, low-voltage detector
(LVI), or clock monitor (CLM)).
After the IDLE1 mode has been released, the normal operation mode is restored.
(1) Releasing IDLE1 mode by non-maskable interrupt request signal or unmasked maskable interrupt request
signal
The IDLE1 mode is released by a non-maskable interrupt request signal or an unmasked maskable interrupt
request signal, regardless of the priority of the interrupt request signal. If the IDLE1 mode is set in an interrupt
servicing routine, however, an interrupt request signal that is issued later is processed as follows.
(a) If an interrupt request signal with a priority lower than that of the interrupt request currently being serviced is
issued, the IDLE1 mode is released, but that interrupt request signal is not acknowledged. The interrupt
request signal itself is retained.
(b) If an interrupt request signal with a priority higher than that of the interrupt request currently being serviced is
issued (including a non-maskable interrupt request signal), the IDLE1 mode is released and that interrupt
request signal is acknowledged.
Caution An interrupt request signal that is disabled by setting the PSC.NMI1M, PSC.NMI0M, and
PSC.INTM bits to 1 becomes invalid and IDLE1 mode is not released.