multiply.abl

来自「16V8例程,应用GEL16V8实现的振荡器,振荡频率为300k-20Hz」· ABL 代码 · 共 113 行

MODULE multiply

TITLE '3 bit multiplier'
"Takes two sets of three bits, provides 6 bit product.
"Demonstrates use of default values for a lower-level
"module. Default values allow the user to use
"a lower level module without specifying signal levels
"or inputs for all of the module's input ports.


"Inputs
	a2, a1, a0, b2, b1, b0        pin ;


"Outputs
	p5, p4, p3, p2, p1, p0        pin istype 'com,invert';


"Set declarations
	aset = [a2,a1,a0];
	bset = [b2,b1,b0];
	product = [p5,p4,p3,p2,p1,p0];


"Sub-module declarations, with default input values
"In this case, all inputs default to 0 if not used.
	adder interface (a=0, b=0, sin=0, cin=0 -> sum, carry);

"Sub-module instances
	ablk1 functional_block adder;
	ablk2 functional_block adder;
	ablk3 functional_block adder;
	ablk4 functional_block adder;
	ablk5 functional_block adder;
	ablk6 functional_block adder;
	ablk7 functional_block adder;
	ablk8 functional_block adder;
	ablk9 functional_block adder;


Equations
	
" This multiplier circuit is constructed of 9 adder blocks 
" connected in a CRAY-type array. Each block as two 
" data bit inputs, plus carry and sum inputs, though the
" carry and sum inputs are not always used. In those 
" cases, the default value is assumed.

	p5 = ablk9.carry;     " Product output bit 5
	p4 = ablk9.sum;       " bit 4 
	p3 = ablk7.sum;       " bit 3
	p2 = ablk4.sum;       " bit 2
	p1 = ablk2.sum;       " bit 1
	p0 = ablk1.sum;       " bit 0

	ablk9.cin = ablk7.carry;
	ablk9.sin = ablk8.carry;
	ablk9.a = a2;
	ablk9.b = b2;

	ablk8.cin = ablk5.carry;
	ablk8.a = a2;
	ablk8.b = b1;

	ablk7.cin = ablk4.carry;
	ablk7.sin = ablk8.sum;
	ablk7.a = a1;
	ablk7.b = b2;

	ablk6.a = a2;              "Assume default values
	ablk6.b = b0;              "for carry and sum inputs

	ablk5.sin = ablk6.sum;
	ablk5.cin = ablk3.carry;
	ablk5.a = a1;
	ablk5.b = b1;

	ablk4.sin = ablk5.sum;
	ablk4.cin = ablk2.carry;
	ablk4.a = a0;
	ablk4.b = b2;

	ablk3.a = a1;
	ablk3.b = b0;

	ablk2.sin = ablk3.sum;
	ablk2.cin = ablk1.carry;
	ablk2.a = a0;
	ablk2.b = b1;

	ablk1.a = a0;
	ablk1.b = b0;

	
Test_vectors 
       ([aset, bset] -> product)
        [  0 ,   0 ] ->    0;
	[  0 ,   1 ] ->    0;
	[  1 ,   2 ] ->    2;
	[  2 ,   3 ] ->    6;
	[  3 ,   4 ] ->   12;
	[  3 ,   5 ] ->   15;
	[  4 ,   5 ] ->   20;
	[  4 ,   6 ] ->   24;
	[  5 ,   6 ] ->   30;
	[  5 ,   7 ] ->   35;
	[  6 ,   7 ] ->   42;
	[  7 ,   7 ] ->   49;


END