INTERUP.TXT
******** 68000 AND 68901 INTERRUPT VECTOR TABLE ******* Note: on the ST, interrupt levels 1, 3, and 5 are not wired (a pin of the 68000 is not connected). The vectors associated with the MFP 68901 are placed in the user interrupt vector area. All MFP interrupts are handled by the 68000 as being at level 6. The internal priority order of the MFP ranges from 15 (max priority) to 0 (min priority). This order is also reflected in the bits in all MFP registers, thus providing a simple correspondence to remember between the bit position used to set an interrupt and its priority level. +------------------------------------------------------------------------+ * Level Address Description * +------------------------------------------------------------------------+ * 7 $7C NMI (Reset) * * 6 $78 MFP 68901 * * 5 $74 * * 4 $70 VBL, frame return * * 3 $6C * * 2 $68 HBL, line return * * 1 $64 * *------------------------------------------------------------------------+ * Level 6: MFP 68901 * * * * 15 $13C Monochrome monitor detection * * 14 $138 RS232 ring indicator * * 13 $134 Timer A (available) * * 12 $130 RS232 receive buffer full * * 11 $12C RS232 receive error * * 10 $128 RS232 transmit buffer empty * * 9 $124 RS232 transmit error * * 8 $120 Timer B, Horizontal interrupt counter * * 7 $11C Disk and DMA controller * * 6 $118 ACIA 6850 ( MIDI and Keyboard ) * * 5 $114 Timer C ( 200 Hz system clock ) * * 4 $110 Timer D ( RS232 clock ) * * 3 $10C Video controller ( operation complete ). * * 2 $108 Serial I/O CTS * * 1 $104 Serial I/O DCD * * 0 $100 Parallel interface BUSY line * * * +------------------------------------------------------------------------+
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