PXN20 Microcontroller Reference Manual, Rev. 1
lxii Freescale Semiconductor
Register Specifications
An Any address register n (example: A3 is address register 3)
Ay,Ax Source and destination address registers, respectively
Dn Any data register n (example: D5 is data register 5)
Dy,Dx Source and destination data registers, respectively
Rc Any control register (example VBR is the vector base register)
Rm MAC registers (ACC, MAC, MASK)
Rn Any address or data register
Rw Destination register w (used for MAC instructions only)
Ry,Rx Any source and destination registers, respectively
Xi Index register i (can be an address or data register: Ai, Di)
Miscellaneous Operands
#<data> Immediate data following the 16-bit operation word of the instruction
<ea> Effective address
<ea>y,<ea>x Source and destination effective addresses, respectively
<label> Assembly language program label
<list> List of registers for MOVEM instruction (example: D3–D0)
<shift> Shift operation: shift left (<<), shift right (>>)
<size> Operand data size: byte (B), word (W), longword (L)
bc Instruction and data caches
dc Data cache
ic Instruction cache
# <vector> Identifies the 4-bit vector number for trap instructions
<> identifies an indirect data address referencing memory
<xxx> identifies an absolute address referencing memory
dn Signal displacement value, n bits wide (example: d16 is a 16-bit displacement)
SF Scale factor (x1, x2, x4 for indexed addressing mode, <<1n>> for MAC operations)
Operations
+ Arithmetic addition or postincrement indicator
– Arithmetic subtraction or predecrement indicator
x Arithmetic multiplication
Table ii. Notational Conventions (continued)
Instruction Operand Syntax