w83637hg Winbond Electronics Corp America, w83637hg Datasheet - Page 22

• Manufacturer Part Number: w83637hg
• Description: Winbond Lpc I/o Lpc I/o
• Manufacturer: Winbond Electronics Corp America

5.4 Serial Port Interface
CTSA#
CTSB#
DSRA#
DSRB#
RTSA#
HEFRAS
RTSB#
ENGMTO
DTRA
PNPCVS
SYMBOL
PIN
49
78
50
79
51
80
52
IN
IN
IN
O
O
O
I/O
IN
IN
8c
8c
8c
cd
cd
cd
t
t
Clear To Send. It is the modem control input.
The function of these pins can be tested by reading bit 4 of the
handshake status register.
Data Set Ready. An active low signal indicates the modem or
data set is ready to establish a communication link and transfer
data to the UART.
UART A Request To Send. An active low signal 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 HEFRAS, which provides the power-on value for CR26
bit 6 (HEFRAS). A 4.7 kΩ is recommended if intends to pull up.
(select 4EH as configuration I/O port′s address)
UART B Request To Send. An active low signal informs the
modem or data set that the controller is ready to send data.
Watch Dog Time-Out enable.
UART A Data Terminal Ready. An active low signal 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 PNPCVS , which provides the power-on value for CR24
bit 0 ( PNPCVS ). A 4.7 kΩ is recommended if intends to pull up.
(clear the default value of FDC, UARTs, PRT, Game port and
MIDI port)
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FUNCTION
Publication Release Date: March, 2006
W83637HF/HG
Revision 1.6