Dma Channels; Table 2-4. Ibc Dma Channel Assignments - Motorola MVME2700 Series Installation And Use Manual

Operating Instructions

DMA Channels

2
IBC
Priority
Sources of Reset
2-10
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 2-4. IBC DMA Channel Assignments

IBC Controller
Label
1 Channel 0 DMA1
2 Channel 1
3 Channel 2
4 Channel 3
5 Channel 4 DMA2
6 Channel 5
7 Channel 6
8 Channel 7
The MVME2700 single board computer has several potential sources of
reset:
1. Power-on reset
2. switch (resets the VMEbus when the MVME2700 is system
RESET
controller)
3. Watchdog timer Reset function controlled by the SGS-Thomson
M48T559 timekeeper device (resets the VMEbus when the
MVME2700 is system controller)
∗
4. function controlled by the Port 92 register in the PIB
ALT_RST
(resets the VMEbus when the MVME2700 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 — Cascaded from DMA1
Serial Port 4 Receiver (Z85230 Port B Rx)
Serial Port 4 Transmitter (Z85230 Port B Tx)
Not Used
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