SAF-C164SM Infineon Technologies, SAF-C164SM Datasheet - Page 147

• Manufacturer Part Number: SAF-C164SM
• Description: 16-Bit CMOS Microcontroller
• Manufacturer: Infineon Technologies

DP0L
P0L Direction Ctrl. Register
DP0H
P0H Direction Ctrl. Register
Bit
DP0X.y
Alternate Functions of PORT0
When an external bus is enabled, PORT0 is used as data bus or address/data bus.
Note that an external 8-bit demultiplexed bus only uses P0L, while P0H is free for IO
(provided that no other bus mode is enabled).
PORT0 is also used to select the system startup configuration. During reset, PORT0 is
configured to input and each line is held high through an internal pull-up device. Each
line can now be individually pulled to a low level (see DC-level specifications in the
respective Data Sheets) through an external pull-down device. A default configuration is
selected when the respective PORT0 lines are at a high level. By pulling individual lines
to a low level, this default can be changed according to the needs of the applications.
The internal pull-up devices are designed such that external pull-down resistors (see
Data Sheet specification) can be used to apply a correct low level. These external
pull-down resistors can remain connected to the PORT0 pins also during normal
operation, however, care must be taken such that they do not disturb the normal function
of PORT0 (this might be the case, for example, if the external resistor is too strong).
On completion of reset, the selected bus configuration will be written to the BUSCON0
register. The configuration of the high byte of PORT0 will be copied into the special
register RP0H. This read-only register holds the selection for the number of chip selects
User’s Manual
15
15
-
-
14
14
-
-
13
13
-
-
Function
Port direction register DP0H or DP0L bit y
DP0X.y = 0: Port line P0X.y is an input (high-impedance)
DP0X.y = 1: Port line P0X.y is an output
12
12
-
-
11
11
-
-
10
10
-
-
ESFR (F100
ESFR (F102
9
9
-
-
8
8
-
-
7-12
DP0L
DP0H
rw
rw
.7
.7
7
7
H
H
/80
/81
DP0L
DP0H
rw
rw
.6
.6
H
H
6
6
)
)
DP0H
DP0L
rw
rw
.5
.5
5
5
DP0L
DP0H
rw
rw
.4
.4
4
4
DP0L
DP0H
Reset Value: - - 00
Reset Value: - - 00
C164CM/C164SM
rw
rw
.3
.3
3
3
DP0L
DP0H
rw
rw
Parallel Ports
.2
.2
2
2
Derivatives
V1.0, 2002-02
DP0L
DP0H
rw
rw
.1
.1
1
1
DP0L
DP0H
rw
rw
.0
.0
0
0
H
H