PARALLEL PORT PIN SIGNALS
512
15 nStrobe/HostClk 33 Host ■ C mode: Negative true = transfer data into
printer input latch on rising edge
■ N mode: Negative true = transfer
Extensibility Request value into printer input
latch on rising edge
16 nSelectIn/1284 Active 34 Host
■ C mode: Negative true = select printer
■ N mode: Used in conjunction with
HostBusy for 1284 hardware handshaking
17 nAutoFd/HostBusy 35 Host ■ C mode: Not used
■ N mode: Used in conjunction with 1284
Active for 1284 hardware handshaking
18 Host Logic High Host ■ Positive true = host signals valid
■ Negative true = host signals invalid
36 Peripheral Logic High Printer
■ Positive true = printer on
■ Negative true = printer off
Parallel port signals (cont'd.)
Pin Signal mode names:
Compatibility/Nibble
Return
pin
Signal
source
Description
