Subtract 2 words

	B	C	D	E	F	G	H	I	J	K	L	M	N	O	P	Q	R	S	T
1	Subtract 2 words (16 bits)																josvandenenden@gmail.com

2
3	bit		15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
4	bit value		32768	16384	8192	4096	2048	1024	512	256	128	64	32	16	8	4	2	1
5
6	Input
7
8	word1 input		1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1
9	decimal value		32768	16384	8192	4096	2048	1024	512	256	128	64	32	16	8	4	2	1	65535
10
11	word2 input		0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1
12	decimal value		0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1	1
13
14
15					Input aid
16
17					bytes1 dec		255		255
18					bytes1 bin		1111 1111		1111 1111						65535
19												copy error			0
20					bytes2 dec		0		1
21					bytes2 bin		0000 0000		0000 0001						1
22												copy error			0
23
24
25	Calculate two's complement word2
26
27	word2 one's com.		1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	0
28
29	carry	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
30	word2 one's com. copy		1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	0
31	one		0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1
32			-----------------------------------------------------------------------------------------------------------------------------------------------------------------+
33	decimal sum	0	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1
34	word2 two's com.		1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1
35
36
37	Output = word1 + two's complement word2
38
39	carry	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	0
40	word1 copy		1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1
41	word2 two's com. copy		1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1
42			-----------------------------------------------------------------------------------------------------------------------------------------------------------------+
43	decimal sum	1	3	3	3	3	3	3	3	3	3	3	3	3	3	3	3	2
44	word1-word2		1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	0
45			32768	16384	8192	4096	2048	1024	512	256	128	64	32	16	8	4	2	0	65534
46
47
48																Decimal check
49																decimal subtraction			65534
50																subtraction error			0
51