Subtract From Accumulator With Shift Specified by TREG
SUBT
7-185
Assembly Language Instructions
Cycles for a Single SUBT 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.
Cycles for a Repeat (RPT) Execution of an SUBT Instruction
Program
Operand
ROM
DARAM
SARAM
External
DARAM
n
n
n
n+p
SARAM
n
n
n, n+1
†
n+p
External
n+nd
n+nd
n+nd
n+1+p+nd
† If the operand and the code are in the same SARAM block.
Example 1
SUBT
DAT127
;(DP = 5: addresses 0280h–02FFh)
Before Instruction
After Instruction
Data Memory
Data Memory
2FFh
06h
2FFh
06h
TREG
08h
TREG
08h
ACC
X
0FDA5h
ACC
1
0F7A5h
C
C
Example 2
SUBT
*
Before Instruction
After Instruction
ARP
1
ARP
1
AR1
800h
AR1
800h
Data Memory
Data Memory
800h
01h
800h
01h
TREG
08h
TREG
08h
ACC
X
0h
ACC
0
FFFFFF00h
C
C
Cycles