Z8F0830HH020SG Datasheet, PDF (42/257 Pages) Zilog, Inc. – High-Performance 8-Bit Microcontrollers

Z8 Encore!^® F0830 Series
Product Specification
24
V_POR
V_VBO
VDD = 0.0V
VDD = 3.3V
Program
Execution
Internal Precision
Oscillator
Crystal
Oscillator
Internal RESET
signal
Oscillator
Start-up
Note: Not to Scale
POR
counter delay
optional XTAL
counter delay
Figure 6. Power-On Reset Operation
Voltage Brown-Out Reset
The devices in the Z8 Encore! F0830 Series provide low Voltage Brown-Out (VBO) pro-
tection. The VBO circuit forces the device to the Reset state, when the supply voltage
drops below the VBO threshold voltage (unsafe level). While the supply voltage remains
below the Power-On Reset threshold voltage (V_POR), the VBO circuit holds the device in
reset.
After the supply voltage exceeds the Power-On Reset threshold voltage, the device pro-
gresses through a full system reset sequence, as described in the POR section. Following
Power-On Reset, the POR status bit in the Reset Status (RSTSTAT) Register is set to 1.
Figure 7 displays the Voltage Brown-Out operation. See the Electrical Characteristics
chapter on page 184 for the VBO and POR threshold voltages (V_VBO and V_POR).
The POR level is greater than the VBO level by the specified hysteresis value. This
ensures that the device undergoes a POR after recovering from a VBO condition.
PS025113-1212
Reset Sources