Z8FMC16100 Series Flash MCU
Product Specification
31
Low-Power Modes
The Z8FMC16100 Series Flash MCU products contain power-saving features. The high-
est level of power reduction is provided by STOP mode. The next level of power reduction
is provided by the HALT mode.
Stop Mode
Execution of the eZ8 CPU’s STOP instruction places the Z8FMC16100 Series Flash MCU
into STOP mode. In STOP mode, the operating characteristics are:
•
•
•
•
•
Primary crystal oscillator and IPO are stopped; XIN and XOUT pins are driven to VSS.
System clock is stopped
eZ8 CPU is stopped
Program counter (PC) stops incrementing
If enabled for operation during STOP mode, the Watch-Dog Timer and its internal RC
oscillator continue to operate.
•
If enabled for operation in STOP mode through the associated Option Bit, the Voltage
Brown-Out protection circuit continues to operate.
•
•
Comparators and voltage reference operate unless disabled.
All other on-chip peripherals are idle
To minimize current in STOP mode, all GPIO pins that are configured as digital inputs
must be driven to one of the supply rails (VCC or GND), the Voltage Brown-Out protection
and the Watch-Dog Timer must be disabled. The device can be brought out of STOP mode
using Stop-Mode Recovery. For more information refer to the Reset and Stop-Mode
Recovery chapter on page 23.
To prevent excess current consumption, STOP mode must not be used if the device is
driven with an external clock source.
Caution:
Halt Mode
Execution of the eZ8 CPU’s HALT instruction places the device into HALT mode. In
HALT mode, the operating characteristics are:
•
Primary crystal oscillator is enabled and continues to operate
PS024604-1005
P R E L I M I N A R Y
Stop Mode
ZILOG [ ZILOG, INC. ]
