7.4. Example Four

The following example shows an ILLEGAL use of Dependent Functions. The structure below includes two END DF tags, which is not allowed.

     TAG Plug and Play Version Number
     TAG Identifier String
     TAG Logical Device ID
     TAG IRQ Format (MASK IRQ 5,IRQ7)
     TAG Start DF (Length 0)
          TAG I/O Format (Length 4, Min Base 0x0378, Max Base 0x0378)
     TAG Start DF (Length 0)
          TAG I/O Format (Length 4, Min Base 0x0278, Max Base 0x0278)
     TAG Start DF (Length 0)
          TAG I/O Format (Length 4, Min Base 0x03BC, Max Base 0x03BC)
     TAG End DF
     TAG Start DF (Length 1 - Priority 1)
          TAG DMA Format (MASK no DMA channel)
     TAG Start DF (Length 1 - Priority 2)
          TAG DMA Format (MASK 5,6,7)
     TAG End DF
     TAG END Tag

The correct structure is:

     TAG Plug and Play Version Number
     TAG Identifier String
     TAG Logical Device ID
     TAG IRQ Format (MASK IRQ 5,IRQ7)
     TAG Start DF (Length 0)
          TAG I/O Format (Length 4, Min Base 0x0378, Max Base 0x0378)
          TAG DMA Format (MASK no DMA channel)
     TAG Start DF (Length 0)
          TAG I/O Format (Length 4, Min Base 0x0278, Max Base 0x0278)
          TAG DMA Format (MASK no DMA channel)
     TAG Start DF (Length 0)
          TAG I/O Format (Length 4, Min Base 0x03BC, Max Base 0x03BC)
          TAG DMA Format (MASK no DMA channel)
     TAG Start DF (Length 1 - Priority 2)
          TAG I/O Format (Length 4, Min Base 0x0378, Max Base 0x0378)
          TAG DMA Format (MASK 5,6,7)
     TAG Start DF (Length 1 - Priority 2)
          TAG I/O Format (Length 4, Min Base 0x0278, Max Base 0x0278)
          TAG DMA Format (MASK 5,6,7)
     TAG Start DF (Length 1 - Priority 2)
          TAG I/O Format (Length 4, Min Base 0x03BC, Max Base 0x03BC)
          TAG DMA Format (MASK 5,6,7)
     TAG End DF
     TAG END Tag