mc68hc05bs8 Freescale Semiconductor, Inc, mc68hc05bs8 Datasheet - Page 36

• Manufacturer Part Number: mc68hc05bs8
• Description: Mc68hc05 Family Of Low-cost Single-chip Microcontrollers.
• Manufacturer: Freescale Semiconductor, Inc

5
5.1.2
The RESET input pin is used to reset the MCU to provide an orderly software start-up procedure.
When using the external reset, the RESET pin must stay low for a minimum of 1.5t
RESET pin contains an internal Schmitt Trigger as part of its input to improve noise immunity.
5.1.3
When the LVR function is enabled, an internal reset is generated if V
Section 13 for value of V
This LVR reset function is enabled/disabled by programming or erasing bit 0 in the EEPROM
Options register ($0200). Refer to Section 4.5.2.
5-2
INTERNAL
INTERNAL
ADDRESS
INTERNAL
OSC2 PIN
CLOCK
RESET
BUS
DATA
BUS
NOTES:
1. OSC2 is not meant to represent frequency. It is only used to represent time.
2. Internal clock, internal address bus, and internal data bus signals are not available externally.
3. Next rising edge of internal clock after rising edge of RESET initiates reset sequence.
VDD
2
2
2
1
RESET Pin
Low Voltage Reset (LVR)
t
VDDR
VDD THRESHOLD (TYPICALLY 1-2V)
t
OXOV
Figure 5-1 Power-On Reset and RESET Timing
LVR
.)
RESETS AND INTERRUPTS
3FFE
NEW
PCL
t
3FFF
CYC
NEW
PCH
t
RL
4064 t
NEW PC
=1.5t
3
CODE
OP
CYC
CYC
3FFE
3FFE
DD
PCH
drops below V
3FFF
PCL
MC68HC05BS8
NEW PC
CODE
LVR
CYC
OP
. (See
. The
TPG