Timers
Base 8051 has 2 timers
- we have 3 in the Atmel 89C55
Timer mode
- Increments every machine cycle (12 clock cycles)
Counter mode
- Increments when T0/T1 go from 1 - 0 (external signal)
Access timer value directly
Timer can cause an interrupt
Timer 1 can be used to provide programmable baud rate for serial communications
Timer/Counter operation
- Mode control register (TMOD)
- Control register (TCON)