| Abbreviation |
MO |
| Arguments |
None. |
| Default |
MOD51 |
| Description |
The MOD51 control defines symbols for the 8051 special function registers. The following symbols are defined: |
| NOTE |
The MOD51 control may be specified only once on the command line or at the top of the source file. |
| See Also |
A51 SAMPLE.A51 MOD51
$MOD51
| Symbol |
Description |
Byte Address |
| P0 |
Port 0 |
80h |
| SP |
Stack pointer |
81h |
| DPL |
Data pointer (low byte) |
82h |
| DPH |
Data pointer (high byte) |
83h |
| TCON |
Counter/Timer control |
88h |
| TMOD |
Counter/Timer operation mode |
89h |
| TL0 |
Counter/Timer 0 (low byte) |
8Ah |
| TL1 |
Counter/Timer 1 (low byte) |
8Bh |
| TH0 |
Counter/Timer 0 (high byte) |
8Ch |
| TH1 |
Counter/Timer 1 (high byte) |
8Dh |
| P1 |
Port 1 |
90h |
| SCON |
Serial port control |
98h |
| SBUF |
Serial port buffer |
99h |
| P2 |
Port 2 |
0A0h |
| IE |
Interrupt Enable |
0A8h |
| P3 |
Port 3 |
0B0h |
| PSW |
Program Status Word |
0D0h |
| ACC |
Accumulator |
0E0h |
| B |
Multiplication Register |
0F0h |
| Symbol |
Description |
Bit Position |
Bit Address |
| CY |
Carry Flag |
PSW.7 |
0D7h |
| AC |
Auxiliary Carry Flag |
PSW.6 |
0D6h |
| F0 |
Flag 0 |
PSW.5 |
0D5h |
| RS1 |
Register Bank Select, Bit 1 |
PSW.4 |
0D4h |
| RS0 |
Register Bank Select, Bit 0 |
PSW.3 |
0D3h |
| OV |
Overflow Bit |
PSW.2 |
0D2h |
| P |
Parity Bit |
PSW.0 |
0D0h |
| TF1 |
Timer-1 Overflow Bit |
TCON.7 |
8Fh |
| TR1 |
Timer-1 RUN Control Bit |
TCON.6 |
8Eh |
| TF0 |
Timer-0 Overflow Bit |
TCON.5 |
8Dh |
| TR0 |
Timer-0 RUN Control Bit |
TCON.4 |
8Ch |
| IE1 |
Interrupt 1 Edge Flag |
TCON.3 |
8Bh |
| IT1 |
Interrupt 1 Control Bit |
TCON.2 |
8Ah |
| IE0 |
Interrupt 0 Edge Flag |
TCON.1 |
89h |
| IT0 |
Interrupt 0 Control Bit |
TCON.0 |
88h |
| SM0 |
Serial Mode Control Bit 0 |
SCON.7 |
9Fh |
| SM1 |
Serial Mode Control Bit 1 |
SCON.6 |
9Eh |
| SM2 |
Serial Mode Control Bit 2 |
SCON.5 |
9Dh |
| REN |
Receiver Enable Bit |
SCON.4 |
9Ch |
| TB8 |
Transmit Bit 8 (9-Bit Mode) |
SCON.3 |
9Bh |
| RB8 |
Receive Bit 8 (9-Bit Mode) |
SCON.2 |
9Ah |
| TI |
Transmitter Interrupt Flag |
SCON.1 |
99h |
| RI |
Receiver Interrupt Flag |
SCON.0 |
98h |
| EA |
Enable all Interrupts |
IE.7 |
0AFh |
| ES |
Enable serial Port Interrupt |
IE.4 |
0ACh |
| ET1 |
Enable Timer 1 Interrupt |
IE.3 |
0ABh |
| EX1 |
Enable External Interrupt 1 |
IE.2 |
0AAh |
| ET0 |
Enable Timer 0 Interrupt |
IE.1 |
0A9h |
| EX0 |
Enable External Interrupt 0 |
IE.0 |
0A8h |
| RD |
Read Data for External Memory |
P3.7 |
0B7h |
| WR |
Write Data for External Memory |
P3.6 |
0B6h |
| T1 |
Timer/Counter 1 Input/Output |
P3.5 |
0B5h |
| T0 |
Timer/Counter 0 Input/Output |
P3.4 |
0B4h |
| INT1 |
Interrupt 1 Input Pin |
P3.3 |
0B3h |
| INT0 |
Interrupt 0 Input Pin |
P3.2 |
0B2h |
| TXD |
Serial Port Transmit Pin |
P3.1 |
0B1h |
| RXD |
Serial Port Receive Pin |
P3.0 |
0B0h |
| PS |
Serial Port Interrupt Priority |
IP.4 |
0BCh |
| PT1 |
Timer 1 Interrupt Priority |
IP.3 |
0BBh |
| PX1 |
External Interrupt 1 Priority |
IP.2 |
0BAh |
| PT0 |
Timer 0 Interrupt Priority |
IP.1 |
0B9h |
| PX0 |
External Interrupt 0 Priority |
IP.0 |
0B8h |