80C186EB/80C188EB, 80L186EB/80L188EB
Table 3. Pin Descriptions
(Continued)
Pin
Pin
Input
Output
Description
Name
Type
Type
States
T0OUT
O
Ð
H(Q)
Timer OUTput
pins can be programmed to provide a
single clock or continuous waveform generation,
T1OUT
R(1)
depending on the timer mode selected.
P(Q)
T0IN
I
A(L)
Ð
Timer INput
is used either as clock or control signals,
depending on the timer mode selected.
T1IN
A(E)
INT0
I
A(E,L)
Ð
Maskable
INTerrupt
input will cause a vector to a
specific Type interrupt routine. To allow interrupt
INT1
expansion, INT0 and/or INT1 can be used with
INT4
INTA0 and INTA1 to interface with an external slave
controller.
INT2/INTA0
I/O
A(E,L)
H(1)
These pins provide a multiplexed function. As inputs,
they provide a maskable
INTerrupt
that will cause
INT3/INTA1
R(Z)
the CPU to vector to a specific Type interrupt routine.
P(1)
As outputs, each is programmatically controlled to
provide an INTERRUPT ACKNOWLEDGE
handshake signal to allow interrupt expansion.
P2.7
I/O
A(L)
H(X)
BI-DIRECTIONAL, open-drain
Port
pins.
P2.6
R(Z)
P(X)
CTSO
I
A(L)
Ð
Clear-To-Send
input is used to prevent the
transmission of serial data on their respective TXD
P2.4/CTS1
signal pin. CTS1 is multiplexed with an input only port
function.
TXD0
O
Ð
H(X)/H(Q)
Transmit Data
output provides serial data
information. TXD1 is multiplexed with an output only
P2.1/TXD1
R(1)
Port
function. During synchronous serial
P(X)/P(Q)
communications, TXD will function as a clock output.
RXD0
I/O
A(L)
R(Z)
Receive Data
input accepts serial data information.
RXD1 is multiplexed with an input only
Port
function.
P2.0/RXD1
H(Q)
During synchronous serial communications, RXD is
P(X)
bi-directional and will become an output for
transmission or data (TXD becomes the clock).
P2.5/BCLK0
I
A(L)/A(E)
Ð
Baud CLocK
input can be used as an alternate clock
source for each of the integrated serial channels.
P2.2/BCLK1
BCLKx is multiplexed with an input only
Port
function,
and cannot exceed a clock rate greater than one-half
the operating frequency of the processor.
P2.3/SINT1
O
Ð
H(X)/H(Q)
Serial INTerrupt
output will go active to indicate
serial channel 1 requires service. SINT1 is
R(0)
multiplexed with an output only
Port
function.
P(X)/P(X)
NOTE:
Pin names in parentheses apply to the 80C188EB/80L188EB.
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