MC68HC05RC8 Datasheet, PDF (31/122 Pages) Freescale Semiconductor, Inc – General Release Specification

Freescale Semiconductor, Inc.
Memory
Input/Output Programming
2.3.3 RAM
The user RAM consists of 352 bytes of a shared stack area. The RAM
starts at address $0020 and ends at address $017F. The stack begins
at address $00FF. The stack pointer can access 64 bytes of RAM in the
range $00FF to $00C0.
NOTE:
Using the stack area for data storage or temporary work locations
requires care to prevent it from being overwritten due to stacking from an
interrupt or subroutine call.
2.4 Input/Output Programming
In user mode, 20 lines (28-pin PDIP or 28-pin SOIC) or 24 lines (44-lead
PLCC) are arranged as three 8-bit I/O ports. These ports are
programmable as either inputs or outputs under software control of the
data direction registers. For detailed information, refer to Section 7.
Parallel Input/Output (I/O).
MC68HC05RC16 — Rev. 3.0
General Release Specification
Memory
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