Chapter 5 External Bus Interface (S12XEBIV4)
MC9S12XE-Family Reference Manual , Rev. 1.19
242
Freescale Semiconductor
5.1.1
Glossary or Terms
5.1.2
Features
The XEBI includes the following features:
•
Output of up to 23-bit address bus and control signals to be used with a non-muxed external bus
•
Bidirectional 16-bit external data bus with option to disable upper half
•
Visibility of internal bus activity
5.1.3
Modes of Operation
•
Single-chip modes
The external bus interface is not available in these modes.
•
Expanded modes
Address, data, and control signals are activated on the external bus in normal expanded mode and
special test mode.
•
Emulation modes
The external bus is activated to interface to an external tool for emulation of normal expanded mode
or normal single-chip mode applications.
bus clock
System Clock. Refer to CRG Block Guide.
expanded modes
Normal Expanded Mode
Emulation Single-Chip Mode
Emulation Expanded Mode
Special Test Mode
single-chip modes
Normal Single-Chip Mode
Special Single-Chip Mode
emulation modes
Emulation Single-Chip Mode
Emulation Expanded Mode
normal modes
Normal Single-Chip Mode
Normal Expanded Mode
special modes
Special Single-Chip Mode
Special Test Mode
NS
Normal Single-Chip Mode
SS
Special Single-Chip Mode
NX
Normal Expanded Mode
ES
Emulation Single-Chip Mode
EX
Emulation Expanded Mode
ST
Special Test Mode
external resource
Addresses outside MCU
PRR
Port Replacement Registers
PRU
Port Replacement Unit
EMULMEM
External emulation memory
access source
CPU or BDM or XGATE
Because
of
an
order
from
the
United
States
International
Trade
Commission,
BGA-packaged
product
lines
and
part
numbers
indicated
here
currently
are
not
available
from
Freescale
for
import
or
sale
in
the
United
States
prior
to
September
2010:
S12XE
products
in
208
MAPBGA
packages