C505_9708 SIEMENS [Siemens Semiconductor Group], C505_9708 Datasheet - Page 88

• Manufacturer Part Number: C505_9708
• Description: 8-Bit CMOS Microcontroller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

The T2CON timer 2 control register is a bit-addressable register which controls the timer 2 function
and the compare mode of registers CRC, CC1 to CC3.
Special Function Register T2CON (Address C8 H )
Bit
T2PS
I3FR
T2R1
T2R0
T2CM
T2I1
T2I0
Semiconductor Group
Bit No.
C8 H
Function
Prescaler select bit
When set, timer 2 is clocked in the “timer“ or “gated timer“ function with 1/12 of the
oscillator frequency. When cleared, timer 2 is clocked with 1/6 of the oscillator
frequency. T2PS must be 0 for the counter operation of timer 2.
External interrupt 3 falling / rising edge flag
Used for capture function in combination with register CRC. If set, a capture to
register CRC (if enabled) will occur on a positive transition at pin P1.0/AN0/INT3/
CC0
Timer 2 reload mode selection
Compare mode bit for registers CRC, CC1 through CC3
When set, compare mode 1 is selected. T2CM = 0 selects compare mode 0.
Timer 2 input selection
T2R1
0
1
1
T2I1
0
0
1
1
MSB
T2PS
CF H
7
The shaded bits are not used for controlling timer/counter 2.
I3FR
CE H
T2I0
0
1
0
1
6
T2R0
X
0
1
CD H
5
–
Function
No input selected, timer 2 stops
Timer function :
input frequency = f
Counter function :
external input signal at pin P1.7 / AN7 / T2
Gated timer function :
input controlled by pin P1.7 / AN7 / T2
Function
Reload disabled
Mode 0 : auto-reload upon timer 2 overflow (TF2)
Mode 1 : reload on falling edge at pin P1.5 / AN5 / T2EX
T2R1
CC H
4
6-26
T2R0
CB H
3
On-Chip Peripheral Components
osc
T2CM
/6 (T2PS = 0) or f
CA H
2
T2I1
C9 H
1
Reset Value : 00X00000 B
LSB
T2I0
C8 H
0
osc
C505 / C505C
/12 (T2PS = 1)
T2CON
1997-08-01