鈥?/div>
Supply
Enable In
Data/Clock
Reset
Output 1/Busy 1
Output 2/Busy 2
Ground
Input 1
Input 2
1鈥搘ire I/O
Enable Out
No Connect
DESCRIPTION
The DS1481 is a dedicated 1鈥搘ire timing generator.
The device is normally used in conjunction with a paral-
lel port controller to provide the necessary interface to
the host processor. Busy signals allow the host proces-
sor to perform other tasks while 1鈥搘ire 鈥渢ime鈥搒lots鈥?are
completed. The DS1481 also saves the state of D/CLK
and RES allowing print spoolers to operate without
affecting 1鈥搘ire communication.
DS1481 based devices can be cascaded. The first
device鈥檚 O1/BSY1 and O2/BSY2 connect to the PC
printer port鈥檚 BUSY and SELECT OUT signals (pins 11
and 13 respectively). The next DS1481 connects its
O1/BSY1 and O2/BSY2 to the first device鈥檚 I1 and I2
respectively. ENO of the first device connects to ENI of
the second device. More DS1481鈥檚 can be stacked in a
similar manner. The last devices I1 and I2 connect to
BUSY and SELECT of the attached printer.
The DS1481鈥檚 3鈥搗olt operation insures compatibility
with most low power parallel ports (i.e., portable com-
puters).
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