The contents of the memory location addressed by the HL register is compared with the contents of the Accumulator. With a true compare, a condition bit is set. Then HL is incre- mented and the Byte Counter (register pair BC) is decremented.
If the HL register pair contains 1111h, memory location 1111h contains 3Bh, the Accu- mulator contains 3Bh, and the Byte Counter contains 0001h. Upon the execution of a CPI instruction, the Byte Counter contains 0000h, the HL register pair contains 1112h, the Z flag in the F register is set, and the P/V flag in the F Register is reset. There is no effect on the contents of the Accumulator or to address 1111h.