mstechca
New Member
After realizing that setting or clearing a port pin can cause an interrupt to occur, it makes LCD programming much easier.
BUT, I have a question.
According to an 8051 manual, If the interrupt for "external interrupt 0" is activated, it states that the program will jump to 0003H. I would assume this is an absolute address since the 8051 can't go past 64K (FFFFH).
It also states that if the interrupt for "external interrupt 0" is activated, the program will jump to 000BH.
Assuming that all interrupts are active, I only have 8 bytes between 0003H, and 000BH for the external interrupt 0.
If I stored a vector address (where the information between 0003H and 000BH points to an address in external memory), then 4 bytes must be all zero's.
But then if I stored actual code in this space, I don't know if the "jumping" code will actually fit, since I need to use a IRET instruction.
Should I just store an address from 0003H to 000BH where the 000BH is the LSB?
BUT, I have a question.
According to an 8051 manual, If the interrupt for "external interrupt 0" is activated, it states that the program will jump to 0003H. I would assume this is an absolute address since the 8051 can't go past 64K (FFFFH).
It also states that if the interrupt for "external interrupt 0" is activated, the program will jump to 000BH.
Assuming that all interrupts are active, I only have 8 bytes between 0003H, and 000BH for the external interrupt 0.
If I stored a vector address (where the information between 0003H and 000BH points to an address in external memory), then 4 bytes must be all zero's.
But then if I stored actual code in this space, I don't know if the "jumping" code will actually fit, since I need to use a IRET instruction.
Should I just store an address from 0003H to 000BH where the 000BH is the LSB?