UPD784026 Renesas Electronics Corporation., UPD784026 Datasheet - Page 679

• Manufacturer Part Number: UPD784026
• Description: 16/8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

22.7 CAUTIONS
(1) If HALT/STOP/IDLE mode (standby mode hereafter) setting is performed when a condition that releases HALT mode
(2) When crystal/ceramic oscillation is used, the EXTC bit must be cleared (0) before use. If the EXTC bit is set (1),
(3) When the STOP mode is used in a system that uses an external clock, the EXTC bit of the OSTS must be set (1). If
(4) In STOP mode and IDLE mode, the CS bit of the A/D converter mode ADM register should be cleared (0).
(5) D/A converter operation is not stopped simply by setting the STOP mode or IDLE mode. In order to reduce the current
(6) Execute a NOP instruction three times after the standby instruction (after the standby mode has been released).
(refer to 22.3.2 HALT Mode Release) is satisfied, standby mode is not entered, and execution of the next instruction,
or a branch to a vectored interrupt service program, is performed. To ensure that a definite standby mode setting is
made, interrupt requests should be cleared, etc. before entering standby mode.
oscillation will stop.
STOP mode setting is performed in a system to which an external clock is input when the EXTC bit of the OSTS is
cleared (0), the current consumption will increase.
When setting the EXTC bit of OSTS to 1, be sure to input a clock in phase reverse to that of the clock input to the X1
pin, to the X2 pin (refer to 4.3.1 Clock Generation Circuit).
consumption, the DACEn (n = 0, 1) bits of the D/A converter mode register (DAM) must both be cleared (0). When
DACEn is cleared (0), the ANOn (n = 0, 1) pin output level becomes high-impedance.
Otherwise, the standby instruction is not executed if execution of the standby instruction conflicts with an interrupt
request, and the interrupt is acknowledged after several instructions that follow the standby instruction have been
executed. The instruction that is executed before the interrupt is acknowledged is the instruction that is started to be
executed within 6 clocks after the standby instruction has been executed.
Example
MOV STBC, #byte
NOP
NOP
NOP
CHAPTER 22 STANDBY FUNCTION
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