| UMBC | CMSC 391 -- Programming Microcontrollers |
| Bit | Symbol | TCON Bit Function |
| 7 | TF1l | Timer 1 Overflow flag. Set when timer rolls from all 1's to 0. Cleared when processor vectors to execute interrupt service routine located at program address 001Bh. |
| 6 | TR1l | Timer 1 run control bit. Set to 1 by program to enable timer to count; cleared to 0 by program to halt timer. |
| 5 | TF0 l | Timer 0 Overflow flag. Set when timer rolls from all 1's to 0. Cleared when processor vectors to execute interrupt service routine located at program address 000Bh. |
| 4 | TR0l | Timer 0 run control bit. Set to 1 by program to enable timer to count; cleared to 0 by program to halt timer. |
| 3 | IE1 l | External interrupt 1 Edge flag. Set to 1 when a high-to-low edge signal is received on port 3.3 ( |
| 2 | IT1 l | External interrupt 1 signal type control bit. Set to 1 by program to enable external interrupt 1 to be triggered by a falling edge signal. Set to 0 by program to enable a low-level signal on external interrupt 1 to generate an interrupt. |
| 1 | IE0 l | External interrupt 0 Edge flag. Set to 1 when a high-to-low edge signal is received on port 3.2 ( |
| 0 | IT0 l | External interrupt 0 signal type control bit. Set to 1 by program to enable external interrupt 1 to be triggered by a falling edge signal. Set to 0 by program to enable a low-level signal on external interrupt 0 to generate an interrupt. |
Bit addressable as TCON.0 to TCON.7
Direct Byte Address is 88h.