DS1481 Datasheet | Dallas Semiconductor

FEATURES PIN ASSIGNMENT VCC ENI O1/BSY1 O2/BSY2 D/CLK RES NC 1 2 3 4 5 6 7 14 13 12 11 10 9 8 I/O ENO I1 I2 NC NC GND - Provides a synchronous interface to Dallas Semiconductor 1- wire devices - patible with low power parallel ports - Can be cascaded with other DS1481’s - Allows print spooler and other processes to run during - Provides high speed muncation with overdrive capable devices .. 1- wire I/O 14- PIN SOIC (150 MIL) - Space saving 14- pin (150 mil), SOIC package PIN DESCRIPTION VCC ENI D/CLK RES O1/BSY1 O2/BSY2 GND I1 I2 I/O ENO NC - - - - - - - - - - - - Supply Enable In Data/Clock Reset Output 1/Busy 1 Output 2/Busy 2 Ground Input 1 Input 2 1- wire I/O Enable Out No Connect DESCRIPTION The DS1481 is a dedicated 1- wire timing generator. The device is normally used in conjunction with a parallel port controller to provide the necessary interface to the host processor. Busy signals allow the host processor to perform other tasks while 1- wire “time- slots” are pleted. The DS1481 also saves the state of D/CLK and RES allowing print spoolers to operate without affecting 1- wire munication. DS1481 based devices can be cascaded. The first device’s O1/BSY1 and O2/BSY2 connect to the PC printer port’s BUSY and SELECT OUT signals (pins 11 and 13 respectively). The next DS1481 connects its O1/BSY1 and O2/BSY2 to the first device’s I1 and I2 respectively. ENO of the first device connects to ENI of the second device. More DS1481’s can be stacked in a similar manner. The last devices I1 and I2 connect to BUSY and SELECT of the attached printer. The DS1481’s 3- volt operation insures patibility with most low power parallel ports (i.e., portable puters). 021798 1/10 OPERATION One wire munication is executed in “time slots”. The DS1481 generates either a read/write bit “time slot” or a reset on the I/O pin. The operation performed is determined by the states of the D/CLK and RES pins as follows: TIME SLOT Read 0, Read 1, Write 1 Write 0 1- wire Reset D/CLK logic...