2-58 Service Guide
Table 2-6NS87338VJG Pin Descriptions
Pin No. I/O Description
/TRK0
(Normal Mode) 35 IFDC Track 0. This input indicates the controller that the head of the
selected floppy disk drive is at track zero.
/TRK0
(PPM Mode) 91 IFDC Track 0. This pin gives an additional Track 0 signal in PPM
Mode when PNF = 0.
VDDB, C 48, 97 Power Supply. This is the 3.3V/5V supply voltage for the
PC87332VJG circuitry.
VSSB-E 40, 7,
88, 59 Ground. This is the ground for the PC87332VJG circuitry.
/WAIT 82 IEPP Wait. This signal is used in EPP mode by the parallel port device
to extend its access cycle. It is an active low signal.
/WDATA
(Normal Mode) 37 OFDC Write Data. This output is the write precompensated serial data
that is written to the selected floppy disk drive. Precompensation is
software selectable.
/WDATA
(PPM Mode) 81 OFDC Write Data. This pin provides an additional Write Data signal in
PPM Mode when PNF=0. (See PE.)
/WGATE
(Normal Mode) 36 OFDC Write Gate. This output signal enables the write circuitry of the
selected disk drive. WGATE has been designated to prevent glitches
during power-up and power-down. This prevents writing to the disk
when power is cycled.
/WGATE
(PPM Mode) 80 OFDC Write Gate. This pin gives an additional Write Gate signal in
PPM mode when PNF = 0.
/WP
(Normal Mode) 34 IFDC Write Protect. This input indicates that the disk in the selected
drive is write protected.
/WP
(PPM Mode) 90 IFDC Write Protect. This pin gives an additional Write Gate signal in
PPM mode when PNF = 0.
/WR 16 IWrite. An active low input to signal a write from the microprocessor to
the controller.
/WRITE 93 OEPP Write Strobe. This signal is used in EPP mode as write strobe.
It is active low.
X1 5IClock. Active clock input signal of 14.318 MHz, 24MHz or 48MHz.
/ZWS 1OZero Wait State. This pin is the Zero Wait State open drain output pin
when bit 6 of FCR is 0. ZWS is driven low when the EPP or ECP is
written, and the access can be shortened.