e8051 USER GUIDE - INTERRUPT VECTORS


This table lists the interrupt sources together with their vector 
addresses implemented in the e8051 core.

Interrupts requested simultaneously at the same priority level are further 
prioritised in the following order (highest priority first).


Source        Vector address        Description

 Reset            0000h         Power-on program execution start.

 IRQP             0033h         ("Power Fail"), always has highest interrupt priority, 
                                not masked internally, but could be externally.

 INT0             0003h         IE0, Interrupt 0
 TF0              000Bh         Timer 0
 INT1             0013h         IE1, Interrupt 1
 TF1              001Bh         Timer 1
 RI0+TI0          0023h         Serial port 0
 TF2              002Bh         Timer 2
	
 RI1+TI1          003Bh         Serial port 1

 EIRQ0            0043h         Extended Interrupts pin EIRQ0
 EIRQ1            004Bh         Extended Interrupts pin EIRQ1
 EIRQ2            0053h         Extended Interrupts pin EIRQ2
 EIRQ3            005Bh         Extended Interrupts pin EIRQ3
 EIRQ4            0063h         Extended Interrupts pin EIRQ4
 EIRQ5            006Bh         Extended Interrupts pin EIRQ5
 EIRQ6            0073h         Extended Interrupts pin EIRQ6
 EIRQ7            007Bh         Extended Interrupts pin EIRQ7

 E2IRQ0           0083h         Extended Interrupts pin E2IRQ0
 E2IRQ1           008Bh         Extended Interrupts pin E2IRQ1
 E2IRQ2           0093h         Extended Interrupts pin E2IRQ2
 E2IRQ3           009Bh         Extended Interrupts pin E2IRQ3
 E2IRQ4           00A3h         Extended Interrupts pin E2IRQ4
 E2IRQ5           00ABh         Extended Interrupts pin E2IRQ5
 E2IRQ6           00B3h         Extended Interrupts pin E2IRQ6
 E2IRQ7           00BBh         Extended Interrupts pin E2IRQ7


Although it is not an interrupt, the unused 8051 instruction (opcode A5h), 
if used, causes a one-byte program "call" to address location 00C3h. This can be 
used as an aid to debugging programs, or to extend the 8051 instruction set 
if required.