ST10F280_12 Datasheet, PDF (116/239 Pages) STMicroelectronics – 16-bit MCU with MAC unit, 512 Kbyte Flash memory and 18 Kbyte RAM

Parallel ports
ST10F280
DP4
Address:
Reset:
Type:
15 14 13 12 11 10
9
-
-
-
-
-
-
-
0xFFCAh / E5h SFR
0x--00h
R/W
8
7
6
5
4
3
2
1
0
- DP4.7 DP4.6 DP4.5 DP4.4 DP4.3 DP4.2 DP4.1 DP4.0
R/W R/W R/W R/W R/W R/W R/W R/W
DP4.y Port direction register DP4 bit y
DP4.y = 0: Port line P4.y is an input (high-impedance)
DP4.y = 1: Port line P4.y is an output
For CAN configuration support (see Chapter 15: CAN modules), Port 4 has a new open
drain function, controlled with the new ODP4 register:
ODP4
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
-
-
-
-
-
-
-
- ODP4.7 ODP4.6 -
-
-
-
-
-
R/W
R/W
Address:
Reset:
Type:
0xF1CAh / E5h ESFR
0x--00h
R/W
ODP4.y Port 4 Open drain control register bit y
ODP4.y = 0: Port line P4.y output driver in push/pull mode
ODP4.y = 1: Port line P4.y output driver in open drain mode if P4.y is not a segment
address line output
Note:
12.6.1
Only bits 6 and 7 are implemented, all other bits will be read as “0”.
Alternate functions of Port 4
During external bus cycles that use segmentation (i.e. an address space above 64K Bytes)
a number of Port 4 pins may output the segment address lines. The number of pins used for
segment address output determines the directly accessible external address space.
The other pins of Port 4 may be used for general purpose I/O. If segment address lines are
selected, the alternate function of Port 4 may be necessary to access e.g. external memory
directly after reset. For this reason Port 4 will be switched to this alternate function
automatically.
The number of segment address lines is selected via PORT0 during reset. The selected
value can be read from bitfield SALSEL in register RP0H (read only) to check the
configuration during run time.
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Doc ID 8673 Rev. 3