Table of Contents
Advertisement
Table 2-10
NS87336VLJ Pin Descriptions (continued)
Pin
No.
/DRV2
49
/DSKCHG
32
(Normal Mode)
/DSKCHG
89
(PPM Mode)
/DSR1
76, 68
/DSR2
/DSTRB
78
/DTR1
71, 63
/DTR2
/ERR
79
/HDSEL
34
(Normal Mode)
/HDSEL
79
(PPM Mode)
IDLE
43
/INDEX
47
/INDEX
94
(Normal Mode)
/INIT
80
(PPM Mode)
I/O
Description
I
FDD Drive2. This input indicates whether a second disk drive has
been installed. The state of this pin is available from Status Register
A in PS/2 mode. (See PNF for further information).
I
Disk Change. The input indicates if the drive door has been opened.
The state of this pin is available from the Digital Input Register. This
pin can also be configured as the RGATE data separator diagnostic
input via the Mode command.
I
Disk Change. This pin offers an additional Disk Change signal in
PPM Mode when PNF = 0.
I
UARTs Data Set Ready. When low, this indicates that the data set
or modem is ready to establish a communications link. The DSR
signal is a modem status input. The CPU tests the /DSR signal by
reading bit 5 (DSR) of the Modem Status Register (MSR) for the
appropriate channel. Bit 5 is the complement of the DSR signal. Bit
1 (DDSR) of the MSR indicates whether the DSR input has changed
state since the previous reading of the MSR.
NOTE: Whenever the DDSR bit of the NSR is set, an interrupt is
generated if Modem Status interrupts are enabled.
O
EPP Data Strobe. This signal is used in EPP mode as data strobe.
It is an active low signal.
O
UARTs Data Terminal Ready. When low, this output indicates to
the modem or data set that the UART is ready to establish a
communications link. The DTR signal can be set to an active low by
programming bit 0 (DTR) of the Modem Control Register to a high
level. A Master Reset operation sets this signal to its inactive (high)
state. Loop mode operation holds this signal to its inactive state.
I
Parallel Port Error. This input is set low by the printer when an error
is detected.
attached to it.
O
FDC Head Select. This output determines which side of the FDD is
accessed. Active selects side 1, inactive selects side 0.
O
FDC Head Select. This pin offers an additional Head Select signal in
PPM Mode when PNF = 0.
O
FDD IDLE. IDLE indicates that the FDC is in the IDLE state and can
be powered down. Whenever the FDC is in IDLE state, or in power-
down state, the pin is active high.
I
Index. This input signals the beginning of a FDD track.
I
Index. This pin gives an additional Index signal in PPM mode when
PNF = 0.
I/O
Initialize.
When this signal is low, it causes the printer to be
initialized. This pin is in a tristate condition 10 ns after a 1 is loaded
into the corresponding Control Register bit. The system should pull
this pin high using a 4.7 KΩ resistor.
This pin has a nominal 25 KOHM pull-up resistor
Advertisement
Table of Contents
