Dma Channels; Sources Of Reset; Table 2-3. Ibc Dma Channel Assignments - Motorola MVME2603-1121A Installation And Use Manual

Programming Considerations

DMA Channels

2
IBC
Priority
1
2
3
4
5
6
7
8

Sources of Reset

2-12
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 Label Controller
Channel 0
Channel 1
DMA1
Channel 2
Channel 3
Channel 4
Channel 5
DMA2
Channel 6
Channel 7
The MVME2603/2604 SBC has nine potential sources of reset:
1. Power-on reset
2. switch (resets the VMEbus when the MVME2603/2604
RESET
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)
4. ∗ function controlled by the Port 92 register in the
ALT_RST
PIB (resets the VMEbus when the MVME2603/2604 is system
controller)
5. PCI/ISA I/O Reset function controlled by the Clock Divisor
register in the PIB
DMA Assignment
Serial Port 3 Receiver (Z85230 Port A Rx)
Serial Port 3 Transmitter (Z85230 Port A Tx)
Floppy Drive Controller
Parallel Port
Not available Ñ Cascaded from DMA1
Serial Port 4 Receiver (Z85230 Port B Rx)
Serial Port 4 Transmitter (Z85230 Port B Tx)
Not Used