W83977G Winbond Electronics Corp America, W83977G Datasheet - Page 17

• Manufacturer Part Number: W83977G
• Description: W83877TF plus KBC, CIR, RTC, Pb-free
• Manufacturer: Winbond Electronics Corp America

Advanced Power Management, continued.
4.3
GP23 (P15)
HEFRAS
nPENPLL
ENCPNP
SINA
SINB
CTSA
CTSB
DSRA
DSRB
RTSA
DCDC
RTSB
DTRA
PNPCSV
DTRB
SYMBOL
SYMBOL
W83977F-A/ W83977G-A/ W83977AF-A/ W83977AG-A
Serial Port Interface
45, 52
PIN
PIN
41
48
42
49
43
50
44
51
I/O 12t
I/O 8t
I/O 8t
I/O 8t
I/O 8t
I/O
I/O
IN t
IN t
IN t
IN t
CR2B bit7, 6=01: General purpose I/O port 2, bit 3. It can be configured
as Keyboard P15 I/O port.
CR2B bit7, 6=11:
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 k
as configuration I/O port address)
UART B 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 n PENPLL , which provides the power-on value for CR24 bit 5 (ENPLL)
and bit 6. A 4.7 k
disabled)
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
(
default value of FDC, UARTs, and PTR)
UART B Data Terminal Ready. An active low signal informs the modem
or data set that controller is ready to communicate.
During power-on reset, this pin is pulled down internally and is defined
as ENCPNP, which provides the power-on value for CR24 bit 1
(ENPNP).
comply PnP mode)
Serial Input. Used to receive serial data through the communication link.
PNPCSV
PNPCSV
). A 4.7 k
A 4.7 k
-9 -
, which provides the power-on value for CR24 bit 0
DCD
Ω
Ω
Ω
Ω
is recommended if intends to pull up. (select 370H
is recommended if intends to pull up. (PLL is
is recommended if intends to pull up. (enable
is recommended if intends to pull up. (clear the
input of UART C. [W83977AF only]
FUNCTION
FUNCTION
Publication Release Date: May 2006
Revision 0.60