XC68HC705JJ7 Motorola, XC68HC705JJ7 Datasheet - Page 32

• Manufacturer Part Number: XC68HC705JJ7
• Description: MICROCONTROLLER
• Manufacturer: Motorola

General Description
1.8 RESET Pin
1.9 IRQ/V
Advance Information
32
PP
NOTE:
Pin
The RESET pin can be used as an input to reset the MCU to a known
startup state by pulling it to the low state. It also functions as an output
to indicate that an internal COP watchdog, illegal address, or low-voltage
reset has occurred. The RESET pin contains a pullup device to allow the
pin to be left disconnected without an external pullup resistor. The
RESET pin also contains a steering diode that, when the power is
removed, will discharge to V
connected between the RESET pin and V
contains an internal Schmitt trigger to improve its noise immunity as an
input.
The IRQ/V
the CPU. The IRQ interrupt function uses the LEVEL bit in the MOR to
provide either negative edge-sensitive triggering or both negative
edge-sensitive and low level-sensitive triggering. If the LEVEL bit is set
to enable level-sensitive triggering, the IRQ/V
resistor to V
it must be tied to the V
Schmitt trigger as part of its input to improve noise immunity.
The voltage on this pin may affect operation if the voltage on the
IRQ/V
condition. The IRQ/V
an EPROM memory location or personality EPROM bit. For more
information, refer to
Characteristics.
Each of the PA0–PA3 I/O pins may be connected as an OR function with
the IRQ interrupt function by the PIRQ bit in the MOR. This capability
allows keyboard scan applications where the transitions or levels on the
I/O pins will behave the same as the IRQ/V
transitions and levels are inverted. The edge or level sensitivity selected
by the LEVEL bit in the MOR for the IRQ/V
PP
pin is above V
PP
DD
input pin drives the asynchronous IRQ interrupt function of
for “wired-OR” operation. If the IRQ/V
General Description
15.14 PEPROM and EPROM Programming
PP
DD
DD
pin should only be taken above V
supply. The IRQ/V
when the device is released from a reset
DD
any charge left on an external capacitor
MC68HC705JJ7 • MC68HC705JP7 — REV 4
SS
PP
PP
. The RESET pin also
PP
PP
pin also applies to the I/O
pin, except that active
pin contains an internal
pin requires an external
PP
pin is not used,
DD
to program
MOTOROLA