Atmel 8051 User Manual

Common Features Description
2-89 Atmel 8051 Microcontrollers Hardware Manual
4316B–8051–02/04
Reset Value = 0000 0000b
Bit addressable
Table 2-9. T2MOD Register - T2MOD (S:C9h)
Timer 2 Mode Control Register
Bit
Number
Bit
Mnemonic Description
7TF2
Timer 2 overflow Flag
TF2 is not set if RCLK=1 or TCLK = 1.
Must be cleared by software.
Set by hardware on timer 2 overflow.
6EXF2
Timer 2 External Flag
Set when a capture or a reload is caused by a negative transition on T2EX pin if
EXEN2=1.
Set to cause the CPU to vector to timer 2 interrupt routine when timer 2 interrupt
is enabled.
Must be cleared by software.
5RCLK
Receive Clock bit
Clear to use timer 1 overflow as receive clock for serial port in mode 1 or 3.
Set to use timer 2 overflow as receive clock for serial port in mode 1 or 3.
4TCLK
Transmit Clock bit
Clear to use timer 1 overflow as transmit clock for serial port in mode 1 or 3.
Set to use timer 2 overflow as transmit clock for serial port in mode 1 or 3.
3EXEN2
Timer 2 External Enable bit
Clear to ignore events on T2EX pin for timer 2 operation.
Set to cause a capture or reload when a negative transition on T2EX pin is
detected, if timer 2 is not used to clock the serial port.
2TR2
Timer 2 Run control bit
Clear to turn off timer 2.
Set to turn on timer 2.
1C/T2#
Timer/Counter 2 select bit
Clear for timer operation (input from internal clock system: F
OSC
).
Set for counter operation (input from T2 input pin).
0CP/RL2#
Timer 2 Capture/Reload bit
If RCLK=1 or TCLK=1, CP/RL2# is ignored and timer is forced to auto-reload on
timer 2 overflow.
Clear to auto-reload on timer 2 overflows or negative transitions on T2EX pin if
EXEN2=1.
Set to capture on negative transitions on T2EX pin if EXEN2=1.
76543210
------T2OEDCEN

Atmel 8051 Specifications

General

Brand	Atmel
Model	8051
Category	Microcontrollers
Language	English