Rabbit 2000 - Sra (Hl)

100 Rabbit 2000/3000 Microprocessor
Description
Arithmetically shifts to the right the bits in the data whose address is
• the data in word register HL, or
• the sum of the data in index register IX and a displacement d,or
• the sum of the data in index register IY and a displacement d.
Bits 7 through 1 are shifted to the next lowest-order bit position (bit 7 is shifted to bit 6, etc.). Bit 7 is also cop-
ied to itself. Bit 0 is shifted to the Carry Flag, CF. See Figure 6 below.
SRA (HL)
SRA (IX+d)
SRA (IY+d)
Opcode Instruction Clocks Operation
CB 2E SRA (HL) 10* (HL) = {(HL)[7],(HL)[7,1]};
CF = (HL)[0]
DD CB d 2E SRA (IX+d) 13** (IX + d) = {(IX + d)[7],(IX + d)[7,1]};
CF = (IX + d)[0]
FD CB d 2E SRA (IY+d) 13** (IY +d) = {(IY + d)[7],(IY + d)[7,1]};
CF = (IY + d)[0]
Clocking: *10 (2,2,1,2,3) **13 (2,2,2,2,2,3)
Flags ALTD I/O
S Z L/V C F R SP S D
• • L • • • •
Figure 6: The bit logic of the SRA instruction.
CF
7
0