Z8F0113HJ005EG Datasheet, PDF (39/245 Pages) Zilog, Inc. – High-Performance 8-Bit Microcontrollers

Z8 Encore! XP^® F0823 Series
Product Specification
24
V_POR
V_VBO
V_CC = 0.0V
Internal Precision
Oscillator
V_CC = 3.3 V
Program
Execution
Internal RESET
signal
Note: Not to Scale
POR
counter delay
Figure 5. Power-On Reset Operation
Voltage Brown-Out Reset
The devices in the Z8 Encore! XP F0823 Series provide low VBO protection. The VBO
circuit senses when the supply voltage drops to an unsafe level (below the VBO threshold 
voltage) and forces the device into the Reset state. While the supply voltage remains
below the POR voltage threshold (V_POR), the VBO block holds the device in the Reset.
After the supply voltage again exceeds the Power-On Reset voltage threshold, the device
progresses through a full System Reset sequence, as described in the Power-On Reset sec-
tion on page 23. Following POR, the POR status bit in the Reset Status (RSTSTAT) Regis-
ter is set to 1. Figure 6 displays Voltage Brown-Out operation. For the VBO and POR
threshold voltages (V_VBO and V_POR), see the Electrical Characteristics chapter on
page 196.
The VBO circuit can be either enabled or disabled during STOP Mode. Operation during
STOP Mode is set by the VBO_AO Flash Option bit. For information about configuring
VBO_AO, see the Flash Option Bits chapter on page 146.
PS024315-1011
PRELIMINARY
Reset Sources