MC68HC05P4A Datasheet, PDF (11/72 Pages) Advanced Analogic Technologies – Microcontrollers

Chapter 1
General Description
1.1 Introduction
The MC68HC05P4A is a 28-pin MCU (microcontroller unit) based on the MC68HC05P4. The memory
map includes 4160 bytes of user ROM and 176 bytes of RAM. The MCU has two 8-bit input/output (I/O)
ports, A and C. Port B has three I/O pins and port D has two pins, one that is I/O and the other input only.
The MC68HC05P4A includes a simple serial I/O peripheral (SIOP) and an on-chip mask programmable
computer operating properly (COP) watchdog circuit.
1.2 Features
Features of the MC68HC05P4A include:
• Low cost
• HC05 core
• 28-pin package
• On-chip oscillator with RC (resistor capacitor) or crystal/ceramic resonator mask options
• 4160 bytes of user read-only memory (ROM), including 16 user vector locations
• ROM security feature⁽¹⁾
• 176 bytes of on-chip random-access memory (RAM)
• 16-bit timer
• 20 bidirectional input/output (I/O) lines, one input-only line
• Mask programmable keyscan (pullups and interrupt) on eight port pins (PA0–PA7)
• Two port pins with high current drive capability
• User mode
• Self-check mode
• Power-saving stop and wait modes
• Edge-sensitive or edge- and level-sensitive interrupt trigger mask option
• Simple serial I/O port
• Mask option selectable computer operating properly (COP) watchdog timer
1. No security feature is absolutely secure. However, Freescale’s strategy is to make reading or copying the ROM difficult for
unauthorized users.
MC68HC05P4A Data Sheet, Rev. 7.1
Freescale Semiconductor
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