Motorola MVME2600 manual DMA Channels, Sources of Reset, IBC DMA Channel Assignments

	Programming Considerations
DMA Channels	2

The PIB supports seven DMA channels. Channels 0 through 3 support 8-bit DMA devices. Channels 5 through 7 are dedicated to 16-bit DMA devices. The channels are allocated as follows:

Table 2-3. IBC DMA Channel Assignments

IBC	IBC	Controller	DMA Assignment
Priority	Label
1	Channel 0	DMA1	Serial Port 3 Receiver (Z85230 Port A Rx)
2	Channel 1		Serial Port 3 Transmitter (Z85230 Port A
			Tx)
3	Channel 2		Floppy Drive Controller
4	Channel 3		Parallel Port
5	Channel 4	DMA2	Not available — Cascaded from DMA1
6	Channel 5		Serial Port 4 Receiver (Z85230 Port B Rx)
7	Channel 6		Serial Port 4 Transmitter (Z85230 Port B
			Tx)
8	Channel 7		Not Used

Sources of Reset

The MVME2603/2604 SBC has eight potential sources of reset:

1.Power-on reset

2.RESET switch (resets the VMEbus when the MVME2603/2604 is system controller)

3.Watchdog timer Reset function controlled by the SGS-Thomson MK48T559 timekeeper device (resets the VMEbus when the MVME2603/2604 is system controller)

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