z16f2811 ZiLOG Semiconductor, z16f2811 Datasheet - Page 72

• Manufacturer Part Number: z16f2811
• Description: High Performance Microcontrollers
• Manufacturer: ZiLOG Semiconductor

System Reset
PS022006-0207
During a System Reset, the ZNEO Z16F Series device is held in Reset for 66 cycles of the
IPO. At the beginning of Reset, all GPIO pins are configured as inputs. All GPIO
programmable pull-ups are disabled.
At the start of a System Reset, the motor control PWM outputs are forced to high-
impedance momentarily. When the option bits that control the off-state have been properly
evaluated, the PWM outputs are forced to the programmed off-state.
During Reset, the ZNEO CPU and on-chip peripherals are non-active; however, the IPO
and WDT oscillator continue to run. During the first 50 clock cycles, the internal option
bit registers are initialized, after which the system clock for the core and peripherals
begins operating. The ZNEO CPU and on-chip peripherals remain non-active through the
next 16 cycles of the system clock, after which the internal reset signal is deasserted.
On Reset, control registers within the register file that have a defined reset value are
loaded with their reset values. Other control registers (including the Flags) and general-
purpose RAM are undefined following Reset. The ZNEO CPU fetches the Reset vector at
program memory address
execution begins at the Reset vector address.
Table 19
text provides more detailed information on the individual Reset sources. Note that a
POR/VBO event always has priority over all other possible reset sources to ensure that a
full System Reset occurs.
Table 19. System Reset Sources and Resulting Reset Action
Operating Mode
NORMAL or HALT modes
STOP mode
lists the System Reset sources as a function of the operating mode. The following
0004H
P R E L I M I N A R Y
System Reset Source
POR/VBO
WDT time-out
when configured for Reset
RESET pin assertion
Write RSTSCR[0] to 1
Fault detect logic reset
POR/VBO
RESET pin assertion
Fault detect logic reset
and loads that value into the program counter. Program
Reset and Stop Mode Recovery
Product Specification
System Reset
System Reset
System Reset
ZNEO
Action
System Reset
System Reset
System Reset
System Reset
System Reset
™
Z16F Series
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