8080 Decrement Instructions
| Computer Science Now | 8080 Decrement Instructions | |
| Syntax: | DCX | B | |
| Description: | Decrement register pair BC to HL | ||
| Code: | 0B | ||
| Format: | Embedded | ||
| Action: | HL = --BC | ||
| Flags: | SZAPC UUUUU | ||
| Syntax: | INR | B | |
| Description: | Increment register C | ||
| Code: | 0C | ||
| Format: | Embedded | ||
| Action: | C = C + 1 | ||
| Flags: | SZAPC SZAPC | ||
| Syntax: | DCR | B | |
| Description: | Decrement register C | ||
| Code: | 0D | ||
| Format: | Embedded | ||
| Action: | C = C - 1 | ||
| Flags: | SZAPC SZAPC | ||
| Syntax: | INX | D | |
| Description: | Increment register pair DE | ||
| Code: | 13 | ||
| Format: | Embedded | ||
| Action: | HL = ++DE | ||
| Flags: | SZAPC UUUUU | ||
| Syntax: | INR | D | |
| Description: | Increment register D | ||
| Code: | 14 | ||
| Format: | Embedded | ||
| Action: | D = D + 1 | ||
| Flags: | SZAPC SZAPC | ||
| Syntax: | DCR | D | |
| Description: | Decrement register D | ||
| Code: | 15 | ||
| Format: | Embedded | ||
| Action: | D = D - 1 | ||
| Flags: | SZAPC SZAPC | ||
| Syntax: | DCX | D | |
| Description: | Decrement register pair DE to HL | ||
| Code: | 1B | ||
| Format: | Embedded | ||
| Action: | HL = --DE | ||
| Flags: | SZAPC UUUUU | ||
| Syntax: | INR | E | |
| Description: | Increment register E | ||
| Code: | 1C | ||
| Format: | Embedded | ||
| Action: | E = E + 1 | ||
| Flags: | SZAPC SZAPC | ||
| Syntax: | DCR | E | |
| Description: | Decrement register E | ||
| Code: | 1D | ||
| Format: | Embedded | ||
| Action: | E = E - 1 | ||
| Flags: | SZAPC SZAPC | ||
| Syntax: | INX | B | |
| Description: | Increment register pair BC | ||
| Code: | 03 | ||
| Format: | Embedded | ||
| Action: | HL = ++BC | ||
| Flags: | SZAPC UUUUU | ||
| Syntax: | INX | H | |
| Description: | Increment register pair HL | ||
| Code: | 23 | ||
| Format: | Embedded | ||
| Action: | HL = ++HL | ||
| Flags: | SZAPC UUUUU | ||
| Syntax: | INR | H | |
| Description: | Increment register H | ||
| Code: | 24 | ||
| Format: | Embedded | ||
| Action: | H = G + 1 | ||
| Flags: | SZAPC SZAPC | ||
| Syntax: | DCR | H | |
| Description: | Decrement register H | ||
| Code: | 25 | ||
| Format: | Embedded | ||
| Action: | H = G - 1 | ||
| Flags: | SZAPC SZAPC | ||
| Syntax: | INR | B | |
| Description: | Increment register B | ||
| Code: | 04 | ||
| Format: | Embedded | ||
| Action: | B = B + 1 | ||
| Flags: | SZAPC SZAPC | ||
| Syntax: | DCX | H | |
| Description: | Decrement register pair HL to HL | ||
| Code: | 2B | ||
| Format: | Embedded | ||
| Action: | HL = --HL | ||
| Flags: | SZAPC UUUUU | ||
| Syntax: | INR | L | |
| Description: | Increment register L | ||
| Code: | 2C | ||
| Format: | Embedded | ||
| Action: | L = L + 1 | ||
| Flags: | SZAPC SZAPC | ||
| Syntax: | DCR | L | |
| Description: | Decrement register L | ||
| Code: | 2D | ||
| Format: | Embedded | ||
| Action: | L = L - 1 | ||
| Flags: | SZAPC SZAPC | ||
| Syntax: | DCR | B | |
| Description: | Decrement register B | ||
| Code: | 05 | ||
| Format: | Embedded | ||
| Action: | B = B - 1 | ||
| Flags: | SZAPC SZAPC | ||
| Syntax: | INX | SP | |
| Description: | Increment register SP | ||
| Code: | 33 | ||
| Format: | Embedded | ||
| Action: | HL = ++SP | ||
| Flags: | SZAPC UUUUU | ||
| Syntax: | INR | M | |
| Description: | Increment memory (HL) | ||
| Code: | 34 | ||
| Format: | Embedded | ||
| Action: | (HL) = (HL) + 1 | ||
| Flags: | SZAPC SZAPC | ||
| Syntax: | DCR | M | |
| Description: | Decrement memory (HL) | ||
| Code: | 35 | ||
| Format: | Embedded | ||
| Action: | (HL) = (HL) - 1 | ||
| Flags: | SZAPC SZAPC | ||
| Syntax: | DCX | SP | |
| Description: | Decrement register SP to HL | ||
| Code: | 3B | ||
| Format: | Embedded | ||
| Action: | HL = --SP | ||
| Flags: | SZAPC UUUUU | ||
| Syntax: | INR | M | |
| Description: | Increment register A | ||
| Code: | 3C | ||
| Format: | Embedded | ||
| Action: | A = A + 1 | ||
| Flags: | SZAPC SZAPC | ||
| Syntax: | DCR | M | |
| Description: | Decrement register A | ||
| Code: | 3D | ||
| Format: | Embedded | ||
| Action: | A = A - 1 | ||
| Flags: | SZAPC SZAPC | ||
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