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ST10F280 Datasheet, PDF (82/186 Pages) STMicroelectronics – 16-BIT MCU WITH MAC UNIT, 512K BYTE FLASH MEMORY AND 18K BYTE RAM
ST10F280
The direction of the pin should be set to output by
the user, otherwise the pin will be in the
high-impedance state and will not reflect the state
of the output latch.
As can be seen from the port structure below, the
user software always has free access to the port
pin even when it is used as a compare output.
This is useful for setting up the initial level of the
pin when using compare mode 1 or the dou-
ble-register mode. In these modes, unlike in com-
pare mode 3, the pin is not set to a specific value
when a compare match occurs, but is toggled
instead.
When the user wants to write to the port pin at the
same time a compare trigger tries to clock the out-
put latch, the write operation of the user software
has priority. Each time a CPU write access to the
port output latch occurs, the input multiplexer of
the port output latch is switched to the line con-
nected to the internal bus. The port output latch
will receive the value from the internal bus and the
hardware triggered change will be lost.
As all other capture inputs, the capture input func-
tion of pins P2.15...P2.0 can also be used as
external interrupt inputs (200 ns sample rate at
40MHz CPU clock).
The upper eight Port 2 lines (P2.15...P2.8) also
can serve as Fast External Interrupt inputs from
EX0IN to EX7IN. (Fast external interrupt sampling
rate is 25ns at 40MHz CPU clock).
P2.15 in addition serves as input for CAPCOM2
timer T7 (T7IN).
The table below summarizes the alternate func-
tions of Port 2.
Port 2 Pin Alternate Function a)
Alternate Function b)
Alternate Function c)
P2.0
P2.1
P2.2
P2.3
P2.4
P2.5
P2.6
P2.7
P2.8
P2.9
P2.10
P2.11
P2.12
P2.13
P2.14
P2.15
CC0IO
CC1IO
CC2IO
CC3IO
CC4IO
CC5IO
CC6IO
CC7IO
CC8IO
CC9IO
CC10IO
CC11IO
CC12IO
CC13IO
CC14IO
CC15IO
-
-
-
-
-
-
-
-
EX0IN
EX1IN
EX2IN
EX3IN
EX4IN
EX5IN
EX6IN
EX7IN
Fast External Interrupt 0 Input
Fast External Interrupt 1 Input
Fast External Interrupt 2 Input
Fast External Interrupt 3 Input
Fast External Interrupt 4 Input
Fast External Interrupt 5 Input
Fast External Interrupt 6 Input
Fast External Interrupt 7 Input
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
T7IN Timer T7 Ext. Count Input
Figure 33 : Port 2 I/O and Alternate Functions
Alternate Function
Port 2
P2.15
P2.14
P2.13
P2.12
P2.11
P2.10
P2.9
P2.8
P2.7
P2.6
P2.5
P2.4
P2.3
P2.2
P2.1
P2.0
a)
CC15IO
CC14IO
CC13IO
CC12IO
CC11IO
CC10IO
CC9IO
CC8IO
CC7IO
CC6IO
CC5IO
CC4IO
CC3IO
CC2IO
CC1IO
CC0IO
b)
EX7IN
EX6IN
EX5IN
EX4IN
EX3IN
EX2IN
EX1IN
EX0IN
c)
T7IN
General Purpose
Input / Output
CAPCOM1
Capture Input / Compare Output
Fast External
Interrupt Input
CAPCOM2
Timer T7 Input
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