| UMBC | CMSC 391 -- Programming Microcontrollers |
8051 PSW
| Bit | SYMBOL | PSW Bit Function |
| 7 | C | (carry flag) -- Set when addition > 0FFh or when subtraction < 0 |
| 6 | AC | (auxiliary carry flag) -- Set when the low nybble affects the high nybble |
| 5 | F0 | (user flag 0) |
| 4 | RS1 | (register bank select 1) |
| 3 | RS0 | (register back select 0) |
| 2 | OV | (overflow flag) -- Set after addition or subtraction, cleared by all others |
| 1 | F1 | (user flag 1) |
| 0 | P | (parity flag) -- Set when the accumulator has an odd number of bits |
Bit addressable as PSW.0 to PSW.7.
Direct Byte Address is 0D0h.