W83977EF Datasheet, PDF (15/150 Pages) Winbond – WINBOND I/O

W83977EF
1.2 General Purpose I/O Port ,continued
SYMBOL PIN
I/O
PANSWIN# 73
IN_t
GP23
I/O_12t
(P15)
SUSC#
(GA20)
39
IN_ts
GP25
I/O₁₂
FUNCTION
Panel Switch input. (CR2B bit 7_6 = 00, default)
General purpose I/O port 2 bit 3. (CR2B bit 7_6 = 01)
Alternate Function from GP23: KBC P15 I/O port
Suspend C input
Alternate Function from GP25: GATE A20 (KBC P21)
General purpose I/O port 2 bit 5.
1.3 Serial Port Interface
SYMBOL PIN
I/O
CTSA#
CTSB#
41
IN_t
48
DSRA#
DSRB#
RTSA#
42
IN_t
49
43
I/O_8t
HEFRAS
RTSB#
50
I/O_8t
FUNCTION
Clear To Send 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 370H 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.
Publication Release Date: April 2003
-9 -
Revision 1.1