Datasheet
71M6543F/71M6543G Data Sheet
v2 41
Table 27: The IEN2 Bit Functions (SFR 0x9A)
Bit
Symbol
Function
IEN2[0]
ES1
ES1 = 0 disables the serial channel 1 interrupt.
Table 28: TCON Bit Functions (SFR 0x88)
Bit Symbol Function
TCON[7]
TF1
Timer 1 overflow flag.
TCON[6]
TR1
Not used for interrupt control.
TCON[5]
TF0
Timer 0 overflow flag.
TCON[4]
TR0
Not used for interrupt control.
TCON[3]
IE1
External interrupt 1 flag.
TCON[2]
IT1
External interrupt 1 type control bit:
0 = interrupt on low level.
1 = interrupt on falling edge.
TCON[1]
IE0
External interrupt 0 flag
TCON[0]
IT0
External interrupt 0 type control bit:
0 = interrupt on low level.
1 = interrupt on falling edge.
Table 29: The T2CON Bit Functions (SFR 0xC8)
Bit
Symbol
Function
T2CON[7]
–
Not used.
T2CON[6]
I3FR
Polarity control for INT3:
0 = falling edge.
1 = rising edge.
T2CON[5]
I2FR
Polarity control for INT2:
0 = falling edge.
1 = rising edge.
T2CON[4:0]
–
Not used.
Table 30: The IRCON Bit Functions (SFR 0xC0)
Bit
Symbol
Function
IRCON[7]
–
Not used.
IRCON[6]
–
Not used.
IRCON[5]
IEX6
1 = External interrupt 6 flag.
IRCON[4]
IEX5
1 = External interrupt 5 flag.
IRCON[3]
IEX4
1 = External interrupt 4 flag.
IRCON[2]
IEX3
1 = External interrupt 3 flag.
IRCON[1]
IEX2
1 = External interrupt 2 flag.
IRCON[0]
–
Not used.
TF0 and TF1 (Timer 0 and Timer 1 overflow flags) is automatically cleared by hardware when the
service routine is called (Signals T0ACK and T1ACK – port ISR – active high when the service
routine is called). IE0, IE1, and IEX2-IEX6 are cleared automatically when hardware causes
execution to vector to the interrupt service routine.