9-bit rotation to the right. The carry is copied into bit 7, and the bit leaving on the right is copied into the carry.
RR A RR B RR C RR D RR E RR H RR L RR (HL) RR (IX+n) RR (IY+n)
Carry becomes the bit leaving on the right, H and N flags are reset, P/V is parity, S and Z are modified by definition.
r denotes 8-bit register.