SAB80C517-M16 SIEMENS [Siemens Semiconductor Group], SAB80C517-M16 Datasheet - Page 158

• Manufacturer Part Number: SAB80C517-M16
• Description: 8-Bit CMOS Single-Chip Microcontroller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Figure 8-6
Special Function Register T2CON (Address 0C8 H )
Bit
I2FR
I3FR
Like the external interrupt 2, the external interrupt 3 can be either positive or negative transition-
activated, depending on bit I3FR in register T2CON. The flag that actually generates this interrupt
is bit IEX3 in register IRCON. In addition, this flag will be set if a compare event occurs at pin
P1.0/INT3/CC0, regardless of the compare mode established and the transition at the respective
pin. The flag IEX3 is cleared by hardware when the service routine is vectored too.
The external interrupts 4 (INT4), 5 (INT5), 6 (INT6) are positive transition-activated. The flags that
actually generate these interrupts are bits IEX4, IEX5, and IEX6 in register IRCON (see figure 8-7).
In addition, these flags will be set if a compare event occurs at the corresponding output pin
P1.1/INT4/CC1, P1.2/INT5/CC2, and P1.3/INT6/CC3, regardless of the compare mode established
and the transition at the respective pin. When an interrupt is generated, the flag that generated it is
cleared by the on-chip hardware when the service routine is vectored too.
The compare timer interrupt is generated by bit CTF in register CTCON (see figure 8-8), which
is set by a rollover in the compare timer. lf a compare timer interrupt is generated, flag CTF will have
to be cleared by software.
Semiconductor Group
0C8 H
0CF H
T2PS
Function
External interrupt 2 falling/rising edge flag. When set, the interrupt 2 request flag
IEX2 will be set on a positive transition at pin P1.4/INT2. I2FR = 0 specifies
external interrupt 2 to be negative-transition activated.
External interrupt 3 falling/rising edge flag. When set, the interrupt 3 request flag
IEX3 will be set on a positive transition at pin P1.0/INT3. I3FR = 0 specifies
external interrupt 3 to be negative-transition active.
These bits are not used for interrupt control.
0CE H
I3FR
0CD H 0CC H 0CB H
I2FR
T2R1
159
T2R0
T2CM
0CA H
0C9 H
T2I1
Interrupt System
0C8 H
T2I0
T2CON