C8051F360/1/2/3/4/5/6/7/8/9
SFR Definition 21.8. TMR2CN: Timer 2 Control
SFR Page:
SFR Address: 0xC8
all pages
(bit addressable)
R/W
R/W
R/W
R/W
R/W
R/W
TR2
Bit2
R
–
R/W
Reset Value
TF2H
Bit7
TF2L
Bit6
TF2LEN TF2CEN T2SPLIT
T2XCLK 00000000
Bit5
Bit4
Bit3
Bit1
Bit0
Bit 7:
TF2H: Timer 2 High Byte Overflow Flag.
Set by hardware when the Timer 2 high byte overflows from 0xFF to 0x00. In 16 bit mode,
this will occur when Timer 2 overflows from 0xFFFF to 0x0000. When the Timer 2 interrupt is
enabled, setting this bit causes the CPU to vector to the Timer 2 interrupt service routine.
TF2H is not automatically cleared by hardware and must be cleared by software.
TF2L: Timer 2 Low Byte Overflow Flag.
Set by hardware when the Timer 2 low byte overflows from 0xFF to 0x00. When this bit is
set, an interrupt will be generated if TF2LEN is set and Timer 2 interrupts are enabled. TF2L
will set when the low byte overflows regardless of the Timer 2 mode. This bit is not automat-
ically cleared by hardware.
Bit 6:
Bit 5:
Bit 4:
TF2LEN: Timer 2 Low Byte Interrupt Enable.
This bit enables/disables Timer 2 Low Byte interrupts. If TF2LEN is set and Timer 2 inter-
rupts are enabled, an interrupt will be generated when the low byte of Timer 2 overflows.
0: Timer 2 Low Byte interrupts disabled.
1: Timer 2 Low Byte interrupts enabled.
TF2CEN: Timer 2 Low-Frequency Oscillator Capture Enable.
This bit enables/disables Timer 2 Low-Frequency Oscillator Capture Mode. If TF2CEN is set
and Timer 2 interrupts are enabled, an interrupt will be generated on a falling edge of the
low-frequency oscillator output, and the current 16-bit timer value in TMR2H:TMR2L will be
copied to TMR2RLH:TMR2RLL. See Section “16. Oscillators” on page 169 for more details.
0: Timer 2 Low-Frequency Oscillator Capture disabled.
1: Timer 2 Low-Frequency Oscillator Capture enabled.
Bit 3:
Bit 2:
T2SPLIT: Timer 2 Split Mode Enable.
When this bit is set, Timer 2 operates as two 8-bit timers with auto-reload.
0: Timer 2 operates in 16-bit auto-reload mode.
1: Timer 2 operates as two 8-bit auto-reload timers.
TR2: Timer 2 Run Control.
This bit enables/disables Timer 2. In 8-bit mode, this bit enables/disables TMR2H only;
TMR2L is always enabled in this mode.
0: Timer 2 disabled.
1: Timer 2 enabled.
Bit 1:
Bit 0:
UNUSED. Read = 0b. Write = don’t care.
T2XCLK: Timer 2 External Clock Select.
This bit selects the external clock source for Timer 2. If Timer 2 is in 8-bit mode, this bit
selects the external oscillator clock source for both timer bytes. However, the Timer 2 Clock
Select bits (T2MH and T2ML in register CKCON) may still be used to select between the
external clock and the system clock for either timer.
0: Timer 2 external clock selection is the system clock divided by 12.
1: Timer 2 external clock selection is the external clock divided by 8. Note that the external
oscillator source divided by 8 is synchronized with the system clock.
258
Rev. 1.0
SILICON [ SILICON ]
