Datasheet

Chapter 21 External Bus Interface (S12XEBIV2)
MC9S12XDP512 Data Sheet, Rev. 2.21
790 Freescale Semiconductor
21.3 Memory Map and Register Definition
This section provides a detailed description of all registers accessible in the XEBI.
21.3.1 Module Memory Map
The registers associated with the XEBI block are shown in Figure 21-2.
21.3.2 Register Descriptions
The following sub-sections provide a detailed description of each register and the individual register bits.
All control bits can be written anytime, but this may have no effect on the related function in certain
operating modes. This allows specific configurations to be set up before changing into the target operating
mode.
NOTE
Depending on the operating mode an available function may be enabled,
disabled or depend on the control register bit. Reading the register bits will
reflect the status of related function only if the current operating mode
allows user control. Please refer the individual bit descriptions.
Register
Name
Bit 7 6 5 4 3 2 1 Bit 0
EBICTL0 R
ITHRS
0
HDBE ASIZ4 ASIZ3 ASIZ2 ASIZ1 ASIZ0
W
EBICTL1 R
EWAITE
0000
EXSTR2 EXSTR1 EXSTR0
W
= Unimplemented or Reserved
Figure 21-2. XEBI Register Summary