Intel 80C196NU 사용자 설명서
8XC196NP, 80C196NU USER’S MANUAL
10-4
P1_MODE 1FD0H
Port
1
Mode
Each bit of P1_MODE controls whether the corresponding 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.
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.
P1_PIN
1FD6H
Port 1 Input
Each bit of P1_PIN reflects the current state of the corresponding
pin, regardless of the pin configuration.
pin, regardless of the pin configuration.
P1_REG
1FD4H
Port 1 Data Output
For an input, set the corresponding P1_REG bit.
For an output, write the data to be driven out by each pin to the
corresponding bit of P1_REG. When a pin is configured as
standard I/O (P1_MODE.
corresponding bit of P1_REG. When a pin is configured as
standard I/O (P1_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 (P1_MODE.
y
= 1), the
associated on-chip peripheral or off-chip component controls the
pin. The CPU can still write to P1_REG, but the pin is unaffected
until it is switched back to its standard I/O function.
pin. The CPU can still write to P1_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 P1_MODE.
(clear P1_MODE.
y
), initialize or overwrite the pin value, then
configure the pin as a special-function signal (set P1_MODE.
y
). In
this way, initialization, fault recovery, exception handling, etc., can
be done without changing the operation of the associated
peripheral.
be done without changing the operation of the associated
peripheral.
T1CONTROL
1F90H
Timer 1 Control
This register enables/disables timer 1, controls whether it counts
up or down, selects the clock source and direction, and
determines the clock prescaler setting.
up or down, selects the clock source and direction, and
determines the clock prescaler setting.
T2CONTROL
1F94H
Timer 2 Control
This register enables/disables timer 2, controls whether it counts
up or down, selects the clock source and direction, and
determines the clock prescaler setting.
up or down, selects the clock source and direction, and
determines the clock prescaler setting.
TIMER1
1F92H
Timer 1 Value
This register contains the current value of timer 1.
TIMER2
1F96H
Timer 2 Value
This register contains the current value of timer 2.
Table 10-2. EPA Control and Status Registers (Continued)
Mnemonic
Address
Description