ST78C34CJ44-F

ST78C34 GENERAL PURPOSE PARALLEL PRINTER PORT WITH 83 BYTE FIFO DESCRIPTION PLCC Package The ST78C34 is a monolithic Bidirectional Parallel port designed to operate as a general purpose I/O port. It contains all the necessary input/output signals to be configured as a CENTRONICS printer port. The ST78C34 is a general purpose input/output con- troller with 83 byte internal FIFO. FIFO operation can be enabled or disabled. For CENTRONICS printer N.C. 7 39 N.C. operation, all registers are mapped to IBM printer port INTSEL 8 38 PD7 registers. D7 9 37 PD6 The ST78C34 is designed to operate as normal 10 36 D6 PD5 printer interface without any additional settings. Con- 11 35 D5 PD4 tents of the FIFO will be cleared after reset or setting 12 ST78C34CJ44 34 PD3 D4 the INIT pin to a low state. The auto FIFO operation starts after the first -ACK is received from the printer. D3 13 33 PD2 Contents of the FIFO transfer to the printer at the D2 14 32 PD1 printer loading speed. D1 15 31 PD0 D0 16 30 GND N.C. 17 29 N.C. FEATURES 83 bytes of printer output FIFO Bi-directional software parallel port Bi-directional I/O ports Register compatible to IBM XT, AT, compatible 386, 486 Selectable interrupt polarity Selectable FIFO interrupts ORDERING INFORMATION Part number Pin Package Operating temperature ST78C34CJ44 44 PLCC 0 C to + 70 C ST78C34CP40 40 PDip 0 C to + 70 C ST78C34IJ44 44 PLCC -40 C to + 85 C ST78C34IP40 40 PDip -40 C to + 85 C Rev. 3.00 6-3 N.C. 18 6 N.C. INT 19 5 PE XTAL1 20 4 -ACK XTAL2 21 3 BUSY -CS 22 SLCT 2 GND 23 -ERROR 1 RESET 24 44 VCC -STROBE 25 43 -IOR -AUTOFDX 26 42 -IOW INIT 27 41 A1 -SLCTIN 28 40 A0ST78C34 Figure 1, PACKAGE DESCRIPTION, ST78C34 Plastic-DIP Package -ERROR 1 40 VCC SLCT 2 39 -IOR BUSY 3 38 -IOW -ACK 4 37 A1 PE 5 36 A0 INTSEL 6 35 N.C. D7 7 34 PD7 D6 8 33 PD6 D5 9 32 PD5 D4 10 31 PD4 D3 11 30 PD3 D2 12 29 PD2 D1 13 28 PD1 D0 14 27 PD0 N.C. 15 26 GND INT 16 25 -SLCTIN XTAL1 17 24 INIT XTAL2 18 23 -AUTOFDX -CS 19 22 -STROBE GND 20 21 RESET Rev. 3.00 6-4 ST78C34CP40