DESCRIPTION | FUNCTIONAL DESCRIPTION | CONNECTION DIAGRAM (20-pin DIP) | FUNCTION SELECT TABLE | TRUTH TABLE | INPUT LOADING / FAN-OUT | DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE | AC CHARACTERISTICS
The 'F381 performs three arithmetic and three logic operations on two
4-bit words, A and B. Two additional select input codes force the
function outputs LOW or HIGH. Carry propagate and generate outputs are
provided for use with the 'F182 carry lookahead generator for high-speed
expansion to longer word lengths. For ripple expansion, refer to the
'F382 ALU data sheet.
o Low Input Loading Minimizes Drive Requirements
o Performs Six Arithmetic and Logic Functions
o Selectable LOW (Clear) and HIGH (Preset) Functions
o Carry Generate and Propagate Outputs for use with Carry Lookahead
Generator
Signals applied to the Select inputs S0-S2 determine the mode of operation, as indicated in the Function Select Table. An extensive listing of input and output levels is shown in the Truth Table. The circuit performs the arithmetic functions for either active HIGH or active LOW operands, with output levels in the same convention. In the Subtract operating modes, it is necessary to force a carry (HIGH for active HIGH operands, LOW for active LOW operands) into the Cn input of the least significant package. The Carry Generate (/G) and Carry Propagate (/P) outputs supply input signals to the 'F182 carry lookahead generator for expansion to longer word length, as shown in Figure a. Note that an 'F382 ALU is used for the most significant package. Typical delays for Figure a are given in Figure b.
Pin Function Pin Function --- ------------------------ --- ------------------------ 1 A1 A operand input 1 20 Vcc 2 B1 B operand input 1 19 A2 A operand input 2 3 A0 A operand input 0 18 B2 B operand input 2 4 B0 B operand input 0 17 A3 A operand input 3 5 S0 Function Select 0 16 B3 B operand input 3 6 S1 Function Select 1 15 Cn Carry input 7 S2 Function Select 2 14 /P Carry Propagate output 8 F0 Function output 0 13 /G Carry Generate output 9 F1 Function output 1 12 F3 Function output 3 10 GND 11 F2 Function output 2
Select ---------- S0 S1 S2 Operation -- -- -- ----------- L L L Clear H L L B Minus A L H L A Minus B H H L A Plus B L L H A xor B H L H A + B L H H AB H H H Preset H = HIGH voltage level; L = LOW voltage level.
Inputs Outputs
------------------ ---------------------
Function S0 S1 S2 Cn An Bn F0 F1 F2 F3 /G /P
------------ -------- -------- ----------- ------
CLEAR 0 0 0 X X X 0 0 0 0 0 0
B MINUS A 1 0 0 0 0 0 1 1 1 1 1 0
0 0 1 0 1 1 1 0 0
0 1 0 0 0 0 0 1 1
0 1 1 1 1 1 1 1 0
1 0 0 0 0 0 0 1 0
1 0 1 1 1 1 1 0 0
1 1 0 1 0 0 0 1 1
1 1 1 0 0 0 0 1 0
A MINUS B 0 1 0 0 0 0 1 1 1 1 1 0
0 0 1 0 0 0 0 1 1
0 1 0 0 1 1 1 0 0
0 1 1 1 1 1 1 1 0
1 0 0 0 0 0 0 1 0
1 0 1 1 0 0 0 1 1
1 1 0 1 1 1 1 0 0
1 1 1 0 0 0 0 1 0
A PLUS B 1 1 0 0 0 0 0 0 0 0 1 1
0 0 1 1 1 1 1 1 0
0 1 0 1 1 1 1 1 0
0 1 1 0 1 1 1 0 0
1 0 0 1 0 0 0 1 1
1 0 1 0 0 0 0 1 0
1 1 0 0 0 0 0 1 0
1 1 1 1 1 1 1 0 0
A xor B 0 0 1 X 0 0 0 0 0 0 1 1
X 0 1 1 1 1 1 1 1
X 1 0 1 1 1 1 1 0
X 1 1 0 0 0 0 0 0
A + B 1 0 1 X 0 0 0 0 0 0 1 1
X 0 1 1 1 1 1 1 1
X 1 0 1 1 1 1 1 1
X 1 1 1 1 1 1 1 0
AB 0 1 1 X 0 0 0 0 0 0 0 0
X 0 1 0 0 0 0 1 1
X 1 0 0 0 0 0 0 0
X 1 1 1 1 1 1 1 0
PRESET 1 1 1 X 0 0 1 1 1 1 1 1
X 0 1 1 1 1 1 1 1
X 1 0 1 1 1 1 1 1
X 1 1 1 1 1 1 1 0
1 = HIGH voltage level; 0 = LOW voltage level; X = immaterial.
Pin Names Description U.L. HIGH/LOW ---------- ----------------------------------- ------------- A0 - A3 A Operand Inputs 0.5 / 1.50 B0 - B3 B Operand Inputs 0.5 / 1.50 S0 - S2 Function Select Inputs 0.5 / 0.375 Cn Carry Input 0.5 / 1.50 /G Carry Generate Output (Active LOW) 25 / 12.5 /P Carry Propagate Output (Active LOW) 25 / 12.5 F0 - F3 Function Outputs 25 / 12.5
Symbol Parameter Min Typ Max Units Conditions
------ -------------------- --- --- --- ----- ----------------------
ICC Power Supply Current 59 89 mA Vcc = Max, S0-S2 = Gnd;
Other Inputs HIGH
TA = +25 C 74F
Vcc = +5.0V TA/Vcc = Com
Symbol Parameter CL Min Typ Max Min Max Units
------ ----------------------------- ----- --- ---- --- --- ---- -----
tPLH Prop Delay Cn to Fi 50 pF 2.5 8.1 12.0 2.5 13.0 ns
tPHL Prop Delay Cn to Fi 50 pF 2.5 5.7 8.0 2.5 9.0 ns
tPLH Prop Delay Any A or B to 50 pF 4.0 10.4 15.0 4.0 16.0 ns
Any F
tPHL Prop Delay Any A or B to 50 pF 3.5 8.2 11.0 3.5 12.0 ns
Any F
tPLH Prop Delay Si to Fi 50 pF 4.5 8.3 20.0 4.5 21.5 ns
tPHL Prop Delay Si to Fi 50 pF 4.0 8.2 11.0 4.0 12.0 ns
tPLH Prop Delay Ai or Bi to /G 50 pF 3.5 6.4 9.0 3.5 10.0 ns
tPHL Prop Delay Ai or Bi to /G 50 pF 4.0 6.8 10.0 4.0 11.0 ns
tPLH Prop Delay Ai or Bi to /P 50 pF 4.0 7.2 10.5 4.0 11.5 ns
tPHL Prop Delay Ai or Bi to /P 50 pF 3.5 6.5 9.5 3.5 10.5 ns
tPLH Prop Delay Si to /G or /P 50 pF 4.0 7.8 12.0 4.0 13.0 ns
tPHL Prop Delay Si to /G or /P 50 pF 4.5 10.2 13.5 4.5 14.5 ns
Data sheet transcription as plain text
No model for this device yet — only the data sheet transcription above.