mc68hc11d0 Freescale Semiconductor, Inc, mc68hc11d0 Datasheet - Page 60

• Manufacturer Part Number: mc68hc11d0
• Description: Mc68hc11d0 Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

5.5 Low-Power Operation
5.5.1 WAIT
5-16
Both STOP and WAIT suspend CPU operation until a reset or interrupt occurs. The
WAIT condition suspends processing and reduces power consumption to an interme-
diate level. The STOP condition turns off all on-chip clocks and reduces power con-
sumption to an absolute minimum while retaining the contents of all 192 bytes of RAM.
The WAI opcode places the MCU in the WAIT condition, during which the CPU regis-
ters are stacked and CPU processing is suspended until a qualified interrupt is detect-
ed. The interrupt can be an external IRQ, an XIRQ, or any of the internally generated
interrupts, such as the timer or serial interrupts. The on-chip crystal oscillator remains
active throughout the WAIT standby period.
The reduction of power in the WAIT condition depends on how many internal clock sig-
VALID SCI REQUEST
RDRF = 1?
TDRE = 1?
IDLE = 1?
OR = 1?
TC = 1?
BEGIN
FLAG
N
N
N
N
N
NO
Figure 5-3 Interrupt Source Resolution within SCI
Y
Y
Y
Y
Y
Freescale Semiconductor, Inc.
For More Information On This Product,
RESETS AND INTERRUPTS
ILIE = 1?
Go to: www.freescale.com
RIE = 1?
TIE = 1?
N
N
N
Y
Y
Y
TCIE = 1?
RE = 1?
RE = 1?
TE = 1?
N
N
N
N
VALID SCI REQUEST
Y
Y
Y
Y
TECHNICAL DATA
INT SOURCE RES