The data sheet states in Terminal Descriptions on page 3 that INTA-D are the interrupt lines. The description in the Modem Control Register on page 29 (Table 12) appears to refer to these as IRQ(A-D). In Table 8 on page 26, MCR bit 3 is labeled "IRQ Enable." Are the INT / IRQ designators all for the same signals? This is potentially confusing.
There is also reference to signals IRQ3-IRQ15, DRO0, DRO1, and DRO3 in Note 9 on page 18 - this is the only mention of these signals, so the note really doesn't seem to make much sense for this part.
One more question: should a weak pulldown be used on the INTA-D signals for the case in which they might be disabled so as not to leave them floating?
