W83977A Winbond Electronics Corp America, W83977A Datasheet - Page 81

• Manufacturer Part Number: W83977A
• Description: Winbond I/O
• Manufacturer: Winbond Electronics Corp America

7.1
The Basic I/O functions of
output port, latching a logic value from input port, inverting the input/output logic value, and steering
Common Interrupt (only available in the second group of the GP I/O port). Common Interrupt is the
ORed function of all interrupt channels in the second group of the GP I/O ports, and it also connects
to a 1ms debounce filter which can reject a noise of 1 ms pulse width or less. There are
registers
is represented as a bit in one of three 8-bit registers. Only 6 bits of GP2 are implemented. Table
7.1.1 shows their combinations of Basic I/O functions, and Table 7.1.2 shows the register bit
assignments of
Table 7.1.1
0 = OUTPUT
1 = INPUT
I/O BIT
Basic I/O functions
0
0
0
0
1
1
1
1
(GP1, GP2, and
GP1, GP2, and GP3.
ENABLE INT BIT
0 = DISABLE
1 = ENABLE
GP3) which are directly connected to those GP I/O ports. Each GP I/O port
W83977TF
0
0
1
1
0
0
1
1
provide several I/O operations including driving a logic value to
0 = NON INVERT
POLARITY BIT
1 = INVERT
-71 -
0
1
0
1
0
1
0
1
Basic non-inverting output
Basic inverting output
Non-inverted output bit value of GP2
drive to Common Interrupt
Inverted output bit value of GP2 drive
to Common Interrupt
Basic non-inverting input
Basic inverting input
Non-inverted input drive to Common
Interrupt
Inverted input drive to Common
Interrupt
Publication Release Date:March 1998
BASIC I/O OPERATIONS
W83977TF
PRELIMINARY
Revision 0.62
three
8-bit