Datasheet

2−21
2.9.1 8052 Standard Interrupt Enable Register
76 5 43210
EA RSV ET2 ES ET1 EX1 ET0 INT0
R/W R/O R/O R/W R/W R/W R/W R/W
BIT NAME RESET FUNCTION
0 INT0 0
Enable or disable external interrupt-0
0
INT0
0
EX0 = 0 External interrupt-0 is disabled.
EX0 = 1 External interrupt-0 is enabled.
1 ET0 0
Enable or disable timer-0 interrupt
1
ET0
0
ET0 = 0 Timer-0 interrupt is disabled.
ET0 = 1 Timer-0 interrupt is enabled.
2 EX1 0
Enable or disable external interrupt-1
2
EX1
0
EX1 = 0 External interrupt-1 is disabled.
EX1 = 1 External interrupt-1 is enabled.
3 ET1 0
Enable or disable timer-1 interrupt
3
ET1
0
ET1 = 0 Timer-1 interrupt is disabled.
ET1 = 1 Timer-1 interrupt is enabled.
4 ES 0
Enable or disable serial port interrupts
4
ES
0
ES = 0 Serial port interrupt is disabled.
ES = 1 Serial port interrupt is enabled.
5 ET2 0
Enable or disable timer-2 interrupt
5
ET2
0
ET2 = 0 Timer-2 interrupt is disabled.
ET2 = 1 Timer-2 interrupt is enabled.
6 RSV 0 Reserved
7 EA 0
Enable or disable all interrupts (global disable)
7
EA
0
EA = 0 Disable all interrupts.
EA = 1 Each interrupt source is individually controlled.
2.9.2 Additional Interrupt Sources
All nonstandard 8052 interrupts (USB, I
2
C, etc.) are connected as an OR to generate an internal INT0. It must be
noted that the external INT0
and INT1 are not used. Furthermore, INT0 must be programmed as an active-low level
interrupt (not edge-triggered). A vector interrupt register is provided to identify all interrupt sources (see vector
interrupt register definition, Section 2.9.3). Up to 64 interrupt vectors are provided. It is the responsibility of the MCU
to read the vector and dispatch the proper interrupt routine.