Typewriter User Manual

MOTOROLA MC68340 USER’S MANUAL 5- 13
Besides the operation code, which specifies the function to be performed, an instruction
defines the location of every operand for the function. Instructions specify an operand
location in one of three ways:
• Register Specification A register field of the instruction contains the number of
the register.
• Effective Address An effective address field of the instruction contains
address mode information.
• Implicit Reference The definition of an instruction implies the use of
specific registers.
The register field within an instruction specifies the register to be used. Other fields within
the instruction specify whether the register is an address or data register and how it is to
be used. The M68000PM/AD,
M68000 Family Programmer’s Reference Manual , contains
detailed register information.
Except where noted, the following notation is used in this section:
Data Immediate data from an instruction
Destination Destination contents
Source Source contents
Vector Location of exception vector
An Any address register (A7–A0)
Ax, Ay Address registers used in computation
Dn Any data register (D7–D0)
Rc Control register (VBR, SFC, DFC)
Rn Any address or data register
Dh, Dl Data registers, high- and low-order 32 bits of product
Dr, Dq Data registers, division remainder, division quotient
Dx, Dy Data registers, used in computation
Dym, Dyn Data registers, table interpolation values
Xn Index register
[An] Address extension
cc Condition code
d
#
Displacement
Example: d
16
is a 16-bit displacement
〈ea〉 Effective address
#〈data〉 Immediate data; a literal integer
label Assembly program label
list List of registers
Example: D3–D0
[...] Bits of an operand
Examples: [7] is bit 7; [31:24] are bits 31–24
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cale Semiconductor,
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