Datasheet

12 - PARALLEL PORTS ST10F269
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The chip select lines of Port 6 have an internal
weak pull-up device. This device is switched on
during reset. This feature is implemented to drive
the chip select lines high during reset in order to
avoid multiple chip selection.
After reset the CS
function must be used, if
selected so. In this case there is no possibility to
program any port latches before. Thus the
alternate function (CS
) is selected automatically in
this case.
Note: The open drain output option can only be
selected via software earliest during the
initialization routine; at least signal CS0
will be in push/pull output driver mode
directly after reset.
Figure 37 : Block Diagram of Port 6 Pins with an Alternate Output Function
MUX
0
1
"0"
Open Drain
Latch
Write ODP6.y
Read ODP6.y
Direction
Latch
Write DP6.y
Read DP6.y
Internal Bus
MUX
0
1
Input
Latch
Clock
P6.y
Output
Buffer
Port Output
Latch
Read P6.y
Write DP6.y
Alternate
Data
Output
MUX
0
1
MUX
0
1
"1"
MUX
Alternate
Function
Enable
y = (0...4, 6, 7)