
W83877ATF
Publication Release Date: April 1998
- 9 -
Version 0.51
1.2 Serial Port Interface, continued
SYMBOL
PIN
I/O
FUNCTION
RTSB
45
I/O
8tc
UART B Request To Send. An active low informs the modem or
data set that the controller is ready to send data.
PGOIQSEL
IN
t
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 4.7 k
is recommended when
intending to pull up at power-on reset.
Function as a InfraRed transmission data line.
Function as a InfraRed receiving line.
IRTX2
IRRX2
95
94
OUT
12t
IN
t
1.3 Multi-Mode Parallel Port
The following pins have eight functions, which are controlled by bits PRTMOD0, PRTMOD1, and
PRTMOD2 of CR0 and CR9 (refer to section 8.0, Extended Functions).
SYMBOL
PIN
I/O
FUNCTION
BUSY
24
IN
t
PRINTER MODE: BUSY
An active high input indicates that the printer is not ready to
receive data. This pin is pulled high internally. Refer to the
description of the parallel port for the definition of this pin in ECP
and EPP mode.
OD
12
EXTENSION FDD MODE: MOB2
This pin is for Extension FDD B; the function of this pin is the
same as that of the MOB pin.
OD
12
EXTENSION 2FDD MODE: MOB2
This pin is for Extension FDD A and B; the function of this pin is
the same as that of the MOB pin.
ACK
26
IN
t
PRINTER MODE: ACK
An active low input on this pin indicates that the printer has
received data and is ready to accept more data. This pin is
pulled high internally. Refer to the description of the parallel port
for the definition of this pin in ECP and EPP mode.
OD
12
EXTENSION FDD MODE: DSB2
This pin is for the Extension FDD B; its functions are the same
as those of the DSB pin.
OD
12
EXTENSION 2FDD MODE: DSB2
This pin is for Extension FDD A and B; the function of this pin is
the same as that of the DSB pin.