Sentry CA756 - Application of the Array-Type Memories

117
116
A B C D E F
A[1] A[2] A[3] A[4] A[5]
The content of memory C (A[2]) is decreased from 5 to 0
in steps of 1.
Therefore, the content of memory A[2] is displayed as 0.
Application of the array-type memories
It is sometimes required to treat two different types of data
as a single group. In this case, memories for data
processing and those for data storage should be kept
separate.
Store data x and y in memories. When a x
value is input, the corresponding y value is
displayed . There will be a total of 15 pieces of
data.
Example program 1
Memory A is used as the data control memory, and
memory B is used for temporary storage of the x data. The
x data are stored in memories C[1] (memory
D) through C [15] (memory R), and the y data are stored in
memories C[16] (memory S) through C[30] (memory Z (7)).
1, , A , : , Defm , 7 , : ,
Lbl , 1 , : , ? , , C , [ , A , ] , : ,
? , , C , [ , A ,+ ,1 ,5, ] , : ,
Lsz , A , : , A , = , 1 , 6 , , Goto ,2 , : ,Goto , 1 , : ,
Lbl, 2 , : ,1 , 5 , , A , : , ? , , B , : ,
B , = , 0 , , Goto , 5 ,: ,
Lbl , 3, :, B . = , C , [ , A , ] , , , Goto , 4 , :,
Dsz, A , : , Goto , 3 , : , Goto , 2 , : ,
Lbl , 4 , : ,C, [ , A , + , 1 , 5 , ], , Goto , 2 ,: ,
Lbl , 5 98 steps
In this program, memories are used as follows :
x data
C[1] C[2] C[3] C[4] C[5] C[6] C[7] C[8]
D E F G H I J K
C[9] C[10] C[11] C[12] C[13] C[14] C[15]
L M N O P Q R
y data
C[16] C[17] C[18] C[19] C[20] C[21] C[22] C[23]
S T U V W X Y Z
C[24] C[25] C[26] C[27] C[28] C[29] C[30]
Z(1) Z(2) Z(3) Z(4) Z(5) Z(6) Z(7)
A [0] A[1] A[2] A[3] A[4] A[5] A[6] A [23] A[24] A[25] A[26] A[27]
B[-1] B [0] B[1] B[2] B[3] B[4] B[5] B[22] B[23] B[24] B[25] B[26]
C[-2] C[-1]C[0] C[1] C[2] C[3] C[4] C[21] C[22] C[23] C[24] C[25]
. .
. .
. .
G[-6] G[-5] G[-4] G[-3] G[-2] G[-1] G[0] G[17] G[18] G[19] G20] G[21]
.
.
.
X [0] X[1] X[2] X[3] X[4]
Y[-1] Y [0] Y[1] Y[2] Y[3]
Z[-2] Z[-1] Z [0] Z[1] Z[2]
The following shows a case in which array-type memories
overlap with standard format memories. This situation
should always be avoided.
Store the numeric values from 1 through 5 in
memories A[1] though A [5] respectively.
5, , C , : , Lbl, 1 , : , C , , A , [ , C , ] , : ,
Dsz , C , : , Goto , 1 , : ,
A , [ , 1 , ] , , A , [ , 2 , ] , , A , [ , 3 , ] , ,
A , [ , 4 , ] , , A , [ , 5 , ] 44 steps
In this program, the values 1 through 5 are stored in the
array-type memories A[1] through A [5] , and memory C is
used as a counter memory. When this program is
executed, the following results are obtained:
As can be seen, the second displayed value (which should
be 2) in A[2] is incorrect. This problem has occurred
because memory A[2] is the same as memory C.