IN A, (n)
Read from port and store in A
\(A \longleftarrow (n)\)
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
|---|---|---|---|---|---|---|---|---|
| 1 | 1 | 0 | 1 | 1 | 0 | 1 | 1 | DB |
| n | ||||||||
This instruction places n onto the bottom half (A0…A7) of the address bus to select the I/O device at one of 256 possible ports. The contents of the Accumulator also appear on the top half (A8…A15) of the address bus at this time. One byte from the selected port is placed on the data bus and written to the Accumulator (Register A).
Flags Affected
| None. |
Opcode Matrix
| A | |
|---|---|
| IN (n) |
IN A,(n)
DBnn211 |
|
Instruction
Opcode hexSize bytesCycle count
| Special |
Last modified November 16, 2021: Optimise I/O pages (a987132)