mc68hc05ct4fn Freescale Semiconductor, Inc, mc68hc05ct4fn Datasheet - Page 21

• Manufacturer Part Number: mc68hc05ct4fn
• Description: Mc68hc05 Family Of Microcontrollers Mcus
• Manufacturer: Freescale Semiconductor, Inc

1.4 Signal Description
1.4.1 V
1.4.2 V
1.4.3 Maskable Interrupt Request (IRQ)
MC68HC05CT4
DD
DD2
and V
and V
—
Rev. 2.0
SS
SS2
The following paragraphs describe the signals.
Power is supplied to the microcontroller’s digital circuits using these two
pins. V
Power is supplied to noise-susceptible circuitry such as the phase-
locked loop (PLL), comparators, and oscillators that require “cleaner”
supplies using these two pins. V
ground.
This pin has a mask option as specified by the user that provides one of
two different choices of interrupt triggering sensitivity. The options are:
The microcontroller unit (MCU) completes the current instruction before
it responds to the interrupt request. When IRQ goes low for at least one
t
requested. When the MCU completes its current instruction, the interrupt
latch is tested. If the interrupt latch contains a logic 1 and the interrupt
mask bit (I bit) in the condition code register is clear, the MCU then
begins the interrupt sequence.
If the option is selected to include level-sensitive triggering, the IRQ input
requires an external resistor to V
The IRQ pin contains an internal Schmitt trigger as part of its input to
improve noise immunity.
ILIH
1. Negative edge-sensitive triggering only
2. Both negative edge-sensitive and level-sensitive triggering
Freescale Semiconductor, Inc.
, a logic 1 is latched internally to signify that an interrupt has been
For More Information On This Product,
DD
is the positive supply and V
Go to: www.freescale.com
General Description
DD2
DD
for wire-OR operation.
is the positive supply and V
SS
is ground.
General Release Specification
General Description
Signal Description
SS2
is