Chapter 2 Port Integration Module (S12XEP100PIMV1)
MC9S12XE-Family Reference Manual , Rev. 1.19
114
Freescale Semiconductor
2.3.12
Port E Data Direction Register (DDRE)
2.3.13
S12X_EBI ports, BKGD pin Pull-up Control Register (PUCR)
Address 0x0009 (PRR)
Access: User read/write
(1)
1. Read: Anytime. In emulation modes, read operations will return the data from the external bus, in all other modes the data source
is depending on the data direction value.
Write: Anytime. In emulation modes, write operations will also be directed to the external bus.
7
6
5
4
3
2
1
0
R
DDRE7
DDRE6
DDRE5
DDRE4
DDRE3
DDRE2
0
0
W
Reset
0
0
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 2-10. Port E Data Direction Register (DDRE)
Table 2-13. DDRE Register Field Descriptions
Field
Description
7-2
DDRE
Port E Data Direction
—
This register controls the data direction of pins 7 through 2.
The external bus function controls the data direction for the associated pins. In this case the data direction bits will
not change.
When operating a pin as a general purpose I/O, the associated data direction bit determines whether it is an input
or output.
1 Associated pin is configured as output.
0 Associated pin is configured as high-impedance input.
1-0
Reserved
—
Port E bit 1 (associated with IRQ) and bit 0 (associated with XIRQ) cannot be configured as outputs. Port E, bits 1
and 0, can be read regardless of whether the alternate interrupt function is enabled.
Address 0x000C (PRR)
Access: User read/write
(1)
1. Read:Anytime in single-chip modes.
Write:Anytime, except BKPUE which is writable in Special Test Mode only.
7
6
5
4
3
2
1
0
R
PUPKE
BKPUE
0
PUPEE
PUPDE
PUPCE
PUPBE
PUPAE
W
Reset
1
1
0
1
0
0
0
0
= Unimplemented or Reserved
Figure 2-11. S12X_EBI ports, BKGD pin Pull-up Control Register (PUCR)
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
