W83877 Winbond Electronics Corp America, W83877 Datasheet - Page 7

• Manufacturer Part Number: W83877
• Description: Winbond I/O
• Manufacturer: Winbond Electronics Corp America

1.2 Serial Port Interface, continued
PHEFRAS
PPNPCVS
RTSB
PGOIQSEL
SOUTB/
IRTX1/
PGMDRQ
DTRA
DTRB
RTSA
SYMBOL
PIN
43
35
46
36
45
I/O
I/O
I/O
I/O
I/O
O
8t
8t
8t
8t
8t
UART B Serial Output. Used to transmit serial data out to the
communication link.
During power-on reset, this pin is pulled up internally and is
defined as PGMDRQ, which provides the power-on value for
CR16 bit 3 (GMDRQ). A 47 k
to pull down at power-on reset.
UART A Data Terminal Ready. An active low informs the
modem or data set that the controller is ready to communicate.
During power-on reset, this pin is pulled down internally and is
defined as PHEFRAS, which provides the power-on value for
CR16 bit 0 (HEFRAS). A 47 k
to pull up at power-on reset.
UART B Data Terminal Ready. An active low informs the
modem or data set that controller is ready to communicate.
UART A Request To Send. An active low informs the modem or
data set that the controller is ready to send data.
During power-on reset, this pin is pulled up internally and is
defined as PPNPCVS, which provides the power-on value for
CR16 bit 2 (PNPCVS). A 47 k
to pull down at power-on reset.
UART B Request To Send. An active low informs the modem or
data set that the controller is ready to send data.
During power-on reset, this pin is pulled down internally and is
defined as PGOIQSEL, which provides the power-on value for
CR16 bit 4 (GOIQSEL). A 47 k
to pull up at power-on reset.
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FUNCTION
Publication Release Date: January 1996
is recommended when intends
is recommended when intends
is recommended when intends
is recommended when intends
W83877F
Revision A2