mc68hc05l25 Freescale Semiconductor, Inc, mc68hc05l25 Datasheet - Page 54

• Manufacturer Part Number: mc68hc05l25
• Description: M68hc05 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Input/Output Ports (I/O)
7.2.3 Port A Pullup Register
Each port A pin may have a software programmable pullup device enabled by the RCR select bits RAH
and RAL. The pullup is activated whenever the corresponding bit in the RCR is set. Since reset clears the
RCR, all pins will initialize with the pullup devices disabled. See
7.5.6 Resistor Control Register
1.
7.2.4 Port A Wired-OR Mode Register
Port A bits 0:3 configured for output pins are wired-OR mode (open drain) only. Port A bits 4:7 configured
for output pins may have software programmable wired-OR mode (open drain) output enabled by the
AWOM bit in the WOMR. Since reset clears the WOMR, the wired-OR mode is disabled on reset. See
7.5.8 Open Drain Output Control
Register.
7.2.5 Key Wakeup Interrupt (KWI)
Four key wakeup inputs (KWI0:KWI3) share pins with port A. Each key wakeup input is enabled by the
corresponding bit in the KWIEN register which resides in the option map. KWI is enabled by the KWIE bit
in the INTCR.
When a falling edge is detected at one of the enabled key wakeup inputs, the KWIF bit in the INTSR is
set and KWI is generated if
KWIE = 1. Each input has a latch which responds only to the falling edge at the pin. All input latches are
cleared at the same time by clearing the KWIF bit. See
Figure
7-9.
MC68HC05L25 Data Sheet, Rev. 3.1
54
Freescale Semiconductor