Z8
®
CPU
User Manual
UM001604-0108 Instruction Description
223
Rotate Right
Syntax
RR dst
Instruction Format
Operation
C ← dst(0)
dst(0) ← dst(1)
dst(1) ← dst(2)
dst(2) ← dst(3)
dst(3) ← dst(4)
dst(4) ← dst(5)
dst(5) ← dst(6)
dst(6) ← dst(7)
dst(7) ← dst(0)
The contents of the destination operand are rotated to the right by one bit position. The ini-
tial value of bit 0 is moved to bit 7 and also into the C Flag, as shown below.
Address modes R or IR can be used to specify a 4-bit Working Register. In this format, the
destination Working Register operand is specified by adding
1110b (Eh) to the high nibble
of the operand. For example, if Working Register R12 (CH) is the destination operand, then
ECh is used as the destination operand in the Op Code.
Cycles
OPC
(Hex)
Address Mode
dst
OPC dst
6E0 R
6E1 IR
Flag Description
C Set if the bit rotated from the least significant bit position was 1 (that is, bit 0 was 1).
Z Set if the result is zero; cleared otherwise.
S Set if the result bit 7 is set; cleared otherwise.
V Set if arithmetic overflow occurred (if the sign of the destination operand changed
during rotation); cleared otherwise.
D Unaffected
H Unaffected
CD7 D6 D5 D4 D3 D2 D1 D0
Note:
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