MC68HC705E5 Datasheet, PDF (21/148 Pages) Freescale Semiconductor, Inc – General Release Specification

Freescale Semiconductor, Inc.
General Description
Functional Pin Description
1.5.1 V_DD and V_SS
Power is supplied to the microcontroller using these two pins. V_DD is the
positive supply and V_SS is ground.
1.5.2 IRQ/V_PP
This pin is used to supply the EPROM with the required programming
voltage. In addition, the mask interrupt request has a programmable
option that provides two different choices of interrupt triggering
sensitivity. The options are:
1. Negative edge-sensitive triggering only
2. Both negative edge-sensitive and level-sensitive triggering
The MCU completes the current instruction before it responds to the
interrupt request. When IRQ/V_PP goes low for at least one t_ILIH, a logic
1 is latched internally to signify an interrupt has been 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_DD for wired-OR operation.
The IRQ/V_PP pin contains an internal Schmitt trigger as part of its input
to improve noise immunity. Refer to Section 4. Interrupts for more
detail.
NOTE: The voltage on the IRQ pin affects the mode of operation. For additional
information, see Section 6. Operating Modes.
MC68HC705E5 — Rev. 1.0
General Release Specification
General Description
For More Information On This Product,
Go to: www.freescale.com