Propeller Manual

ROL – Assembly Language Reference
ROL
Instruction: Rotate value left by specified number of bits.
ROL Value, 〈#〉 Bits
Result: Value is rotated left by Bits.
•
Value (d-field) is the register to rotate left.
•
Bits (s-field) is a register or a 5-bit literal whose value is the number of bits to rotate
left.
Opcode Table:
–INSTR– ZCRI –CON– –DEST– –SRC– Z Result C Result Result Clocks
001001 001i 1111 ddddddddd sssssssss
Result = 0 D[31] Written 4
Concise Truth Table:
In Out
Destination Source Z C Effects Destination Z C
$0000_0000; 0 $0000_0001; 1 - -
wz wc
$0000_0000; 0 1 0
$8765_4321; -2,023,406,815 $0000_0004; 4 - -
wz wc
$7654_3218; 1,985,229,336 0 1
$7654_3218; 1,985,229,336 $0000_000C; 12 - -
wz wc
$4321_8765; 1,126,270,821 0 0
$4321_8765; 1,126,270,821 $0000_0010; 16 - -
wz wc
$8765_4321; -2,023,406,815 0 0
Explanation
ROL (Rotate Left) rotates Value left, Bits times. The MSBs rotated out of Value are rotated
into its LSBs.
If the
WZ effect is specified, the Z flag is set (1) if the resulting Value equals zero. If the WC
effect is specified, at the end of the operation, the C flag is set equal to Value’s original bit
31. The result is written to Value unless the
NR effect is specified.
Page 344 · Propeller Manual v1.1