SQRS
Square Value and Subtract Previous Product
7-170
Syntax
SQRS
dma
Direct addressing
SQRS
ind [, ARn]
Indirect addressing
Operands
dma:
7 LSBs of the data-memory address
n:
Value from 0 to 7 designating the next auxiliary register
ind:
Select one of the following seven options:
* *+ *– *0+ *0– *BR0+ *BR0–
SQRS
dma
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
1
0
1
0
0
1
1
0
dma
SQRS
ind [, ARn]
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
1
0
1
0
0
1
1
1
ARU
N
NAR
Note:
ARU, N, and NAR are defined in Section 6.3,
Indirect Addressing Mode (page 6-9).
Execution
Increment PC, then ...
(ACC) – shifted (PREG)
→
ACC
(data-memory address)
→
TREG
(TREG)
(data-memory address)
→
PREG
Status Bits
Affected by
Affects
OVM and PM
OV and C
Description
The content of the PREG, shifted as defined by the PM status bits, is sub-
tracted from the accumulator. Then the addressed data-memory value is
loaded into the TREG, squared, and stored in the PREG.
Words
1
Cycles for a Single SQRS Instruction
Program
Operand
ROM
DARAM
SARAM
External
DARAM
1
1
1
1+p
SARAM
1
1
1, 2
†
1+p
External
1+d
1+d
1+d
2+d+p
† If the operand and the code are in the same SARAM block
Opcode
Cycles