CONTROL REGISTERS
S3C80A5B
4-28
T1CON
— Timer 1 Control Register
FAH
Set 1
Bit Identifier
.7
.6
.5
.4
.3
.2
.1
.0
RESET Value
0
0
0
0
0
0
0
0
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Addressing Mode
Register addressing mode only
.7–.6
Timer 1 Input Clock Selection Bits
0
0
f
OSC
/4
0
1
f
OSC
/8
1
0
f
OSC
/16
1
1
Internal clock (counter a flip-flop, T-FF)
.5–.4
Timer 1 Operating Mode Selection Bits
0
0
Interval timer mode (counter cleared by match signal)
0
1
Overflow mode (OVF interrupt can occur)
1
0
Overflow mode (OVF interrupt can occur)
1
1
Overflow mode(OVF interrupt can occur)
.3
Timer 1 Counter Clear Bit
0
No effect (when write)
1
Clear T1 counter, T1CNT (when write)
.2
Timer 1 Overflow Interrupt Enable Bit
(note)
0
Disable T1 overflow interrupt
1
Enable T1 overflow interrupt
.1
Timer 1 Match/Capture Interrupt Enable Bit
0
Disable T1 match interrupt
1
Enable T1 match interrupt
.0
Timer 1 Match/Capture Interrupt Pending Flag
0
No T1 match interrupt pending (when read)
0
Clear T1 match interrupt pending condition (when write)
1
T1 match interrupt is pending (when read)
1
No effect (when write)
NOTE
: A timer 1 overflow interrupt pending condition is automatically cleared by hardware. However, the timer 1 match/
capture interrupt, IRQ1, vector F6H, must be cleared by the interrupt service routine.