xitjuvla
Newbie level 3
I have a 8086 - 8259a related problem I really need help solving.
I have programmed the 8259a interrupt controller and it interfaces with the CPU just fine except the CPU doesn't wait for the interrupt vector to be set on the D[0..7] BUS! Instead it reads the old BUS value and executes the wrong interrupt. So if I request interrupts 0, 1, 2 consecutively on the 8259 the CPU will execute unknown interrupt (depending on the last bus cycle) then interrupt 0, then interrupt 2.
I am using the bus transceiver connected to the DT/R 8086 pin.
PLEASE HELP, I've been trying to solve this for the past 12 hours!
Thank you!
Also, any working 8086 proteus designs using 8259 and/or 8254 would be useful if you could share them!
I have programmed the 8259a interrupt controller and it interfaces with the CPU just fine except the CPU doesn't wait for the interrupt vector to be set on the D[0..7] BUS! Instead it reads the old BUS value and executes the wrong interrupt. So if I request interrupts 0, 1, 2 consecutively on the 8259 the CPU will execute unknown interrupt (depending on the last bus cycle) then interrupt 0, then interrupt 2.
I am using the bus transceiver connected to the DT/R 8086 pin.
PLEASE HELP, I've been trying to solve this for the past 12 hours!
Thank you!
Also, any working 8086 proteus designs using 8259 and/or 8254 would be useful if you could share them!