Intel 8XC196MC User Manual page 243

8XC196MC, MD, MH USER'S MANUAL
Table 11-3. EPA Control and Status Registers (Continued)
Mnemonic
INT_PEND 0009H
INT_PEND1 0012H
P2_DIR 1FD2H
P7_DIR
P2_MODE 1FD0H
P7_MODE
P0_PIN 1FA8H
P1_PIN 1FA9H
P2_PIN 1FD6H
P7_PIN
P2_REG 1FD4H
P7_REG
11-4
Address
MC MD MH
0009H 0009H
0012H 0012H
1FD2H 1FD2H
— 1FD3H —
1FD0H 1FD0H
— —
1FD1H
1FA8H 1FDAH
1FA9H 1F9FH
1FD6H 1FD6H
— 1FD7H —
1FD4H 1FD4H
— 1FD5H —
Get other manuals https://www.bkmanuals.com
Description
Interrupt Pending
Any set bit in this 8-bit register indicates a pending
interrupt request.
Interrupt Pending 1
Any set bit in this 8-bit register indicates a pending
interrupt request.
Port x Direction
Each bit of P x _DIR controls the direction of the
corresponding pin. Clearing a bit configures a pin
as a complementary output; setting a bit
configures a pin as an input or open-drain output.
(Open-drain outputs require external pull-ups.)
Port x Mode
Each bit of P x _MODE controls whether the corre-
sponding pin functions as a standard I/O port pin
or as a special-function signal. Setting a bit
configures a pin as a special-function signal;
clearing a bit configures a pin as a standard I/O
port pin.
Port x Input
Each bit of P x _PIN reflects the current state of the
corresponding pin, regardless of the pin configu-
ration.
Port x Data Output
For an input, set the corresponding P x _REG bit.
For an output, write the data to be driven out by
each pin to the corresponding bit of P x _REG.
When a pin is configured as standard I/O
(P x _MODE. y = 0), the result of a CPU write to
P x _REG is immediately visible on the pin. When a
pin is configured as a special-function signal
(P x _MODE. y = 1), the associated on-chip
peripheral or off-chip component controls the pin.
The CPU can still write to P x _REG, but the pin is
unaffected until it is switched back to its standard
I/O function.
This feature allows software to configure a pin as
standard I/O (clear P x _MODE. y ), initialize or
overwrite the pin value, then configure the pin as a
special-function signal (set P x _MODE. y ). In this
way, initialization, fault recovery, exception
handling, etc., can be done without changing the
operation of the associated peripheral.