System information

3.5.3 Increment and Decrement Instructions
The 8080 provides instructions for incrementing or decrementing single- and double precision
registers. The instructions are described in Table 3-6.
Table 3-6. Increment and Decrement Instructions
Form with
Bit Value Example Meaning
INR e3 INR E Single-precision increment register. e3 produces one of A,
B, C, D, E, H, L, M.
DCR e3 DCR A Single-precision decrement register. e3 produces one of A,
B, C, D, E, H, L, M.
INX e3 INX SP Double-precision increment register pair. e3 must be to B,
D, H, or SP.
DCX e3 DCX B Double-precision decrement register pair. e3 must be
equivalent to B, D, H, or SP.
3.5 Operation Codes CP/M Operating System Manual
3-20