Datasheet

Chapter 18 Memory Mapping Control (S12XMMCV3)
MC9S12XDP512 Data Sheet, Rev. 2.21
Freescale Semiconductor 687
18.5.3.3 ROM Control in Normal Expanded Mode
In normal expanded mode the external bus will be connected to the application. If the ROMON bit is set,
the internal FLASH provides the data. If the ROMON bit is cleared, the application memory provides the
data (see Figure 18-29).
Figure 18-29. ROM in Normal Expanded Mode
ROMON = 1
Application
MCU
ROMON = 0
Application
MCU
Flash
Memory
Memory