user manual

Memory
General Release Specification MC68HC05RC16 — Rev. 3.0
30 Memory MOTOROLA
2.3.1 ROM
The user ROM consists of 15,920 bytes of ROM located from $0180 to
$3FAF and 16 bytes of user vectors located from $3FF0 to $3FFF.
The burn-in ROM is located from $3FB0 to $3FEF.
Ten of the user vectors, $3FF6–$3FFF, are dedicated to reset and
interrupt vectors. The six remaining locations — $3FF0, $3FF1, $3FF2,
$3FF3, $3FF4, and $3FF5 — are general-purpose user ROM locations.
2.3.2 ROM Security
Security has been incorporated into the MC68HC05RC16 to prevent
external viewing of the ROM contents. This feature ensures that
customer-developed software remains proprietary.
1
1. No security feature is absolutely secure. However, Motorola’s strategy is to make reading or
copying the ROM difficult for unauthorized users.
$001A Reserved R RRRRRRR
$001B Reserved R RRRRRRR
$001C Reserved R RRRRRRR
$001D Reserved R RRRRRRR
$001E Reserved R RRRRRRR
$001F Reserved R RRRRRRR
R= Reserved
Addr. Register Bit 7 6 5 4 3 2 1 Bit 0
Figure 2-2. I/O Registers (Continued)