
CYRF69213
Document #: 001-07552 Rev. *B
Page 12 of 85
specified as part of the instruction opcode. Operand 1 is added
to the X register forming an address that points to a location in
either the RAM memory space or the register space that is the
source for the instruction. Arithmetic instructions require two
sources; the second source is the A register or X register
specified in the opcode. Instructions using this addressing
mode are two bytes in length.
Examples
Destination Direct
The result of an instruction using this addressing mode is
placed within either the RAM memory space or the register
space. Operand 1 is an address that points to the location of
the result. The source for the instruction is either the A register
or the X register, which is specified as part of the instruction
opcode. Arithmetic instructions require two sources; the
second source is the location specified by Operand 1. Instruc-
tions using this addressing mode are two bytes in length.
Examples
Destination Indexed
The result of an instruction using this addressing mode is
placed within either the RAM memory space or the register
space. Operand 1 is added to the X register forming the
address that points to the location of the result. The source for
the instruction is the A register. Arithmetic instructions require
two sources; the second source is the location specified by
Operand 1 added with the X register. Instructions using this
addressing mode are two bytes in length.
Example
Destination Direct Source Immediate
The result of an instruction using this addressing mode is
placed within either the RAM memory space or the register
space. Operand 1 is the address of the result. The source for
the instruction is Operand 2, which is an immediate value.
Arithmetic instructions require two sources; the second source
is the location specified by Operand 1. Instructions using this
addressing mode are three bytes in length.
Examples
Destination Indexed Source Immediate
The result of an instruction using this addressing mode is
placed within either the RAM memory space or the register
space. Operand 1 is added to the X register to form the
address of the result. The source for the instruction is Operand
2, which is an immediate value. Arithmetic instructions require
two sources; the second source is the location specified by
Operand 1 added with the X register. Instructions using this
addressing mode are three bytes in length.
Table 11.Source Indexed
Opcode
Operand 1
Instruction
Source Index
ADD
A,
[X+7]
;In this case, the value in
;the memory location at
;address X + 7 is added with
;the Accumulator, and the
;result is placed in the
;Accumulator.
MOV
X,
REG[X+8]
;In this case, the value in
;the register space at
;address X + 8 is moved to
;the X register.
Table 12.Destination Direct
Opcode
Operand 1
Instruction
Destination Address
ADD
[7],
A
;In this case, the value in
;the memory location at
;address 7 is added with the
;Accumulator, and the result
;is placed in the memory
;location at address 7. The
;Accumulator is unchanged.
MOV
REG[8],
A
;In this case, the Accumula-
;tor is moved to the regis-
;ter space location at
;address 8. The Accumulator
;is unchanged.
Table 13.Destination Indexed
Opcode
Operand 1
Instruction
Destination Index
ADD
[X+7],
A
;In this case, the value in the
;memory location at address X+7
;is added with the Accumulator,
;and the result is placed in
;the memory location at address
;x+7. The Accumulator is
;unchanged.
Table 14.Destination Direct Immediate
Opcode
Instruction
Operand 1
Operand 2
Immediate Value
Destination Address
ADD
[7],
5
;In this case, value in the mem-
;ory location at address 7 is
;added to the immediate value of
;5, and the result is placed in
;the memory location at address 7.
MOV
REG[8],
6
;In this case, the immediate
;value of 6 is moved into the
;register space location at
;address 8.
Table 15.Destination Indexed Immediate
Opcode
Instruction
Operand 1
Destination Index
Operand 2
Immediate Value
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