Lenovo PC 300PL Technical Information Manual 6562, 6592 - Page 67

Appendix C. IRQ and DMA Channel Assignments Appendix C. IRQ and DMA Channel Assignments The following tables list the IRQ (interrupt request) and DMA (direct memory access) channel assignments for PC 300PL computers. Table 55. IRQ Channel Assignments IRQ System Resource NMI Critical system error SMI System management interrupt - power management 0 Reserved, internal timer 1 Reserved, keyboard buffer full 2 Reserved, cascade interrupt from slave PIC 3 Serial port 2 if enabled; otherwise, user available for ISA or PCI bus 4 Serial port 1 if enabled; otherwise, user available for ISA bus 5 Parallel port 2 if enabled; otherwise, user available for ISA or PCI bus 6 Diskette drive controller 7 Parallel port 1 if enabled; otherwise, user available for ISA bus 8 Reserved, real-time clock 9 User available for ISA or PCI bus 10 User available for ISA or PCI bus 11 User available for ISA or PCI bus 12 System board mouse port if enabled; otherwise, user available for ISA or PCI bus 13 Reserved, math coprocessor 14 IDE channel 1 if enabled; otherwise user available for ISA or PCI bus 15 IDE channel 2 if enabled; otherwise user available for ISA or PCI bus Note: Audio IRQ and DMA resources are required and are assigned by the Plug and Play BIOS or operating system. Table 56. DMA Channel Assignments DMA Channel Data Width System Resource 0 8 bits only User available for ISA bus 1 8 bits only User available for ISA bus 2 8 bits only Reserved, floppy 3 8 bits only Parallel port if ECP; otherwise user available for ISA bus 4 Reserved-cascade channel 5 16 bits only User available for ISA bus 6 16 bits only User available for ISA bus 7 16 bits only User available for ISA bus Note: Channels 0-3 can transfer data in 64 KB pages; channels 5-7 can transfer data in 128 KB pages. © Copyright IBM Corp. 1997 55