He section, Unsupported pc/104, Interface features – Eurotech Appliances ZEUS PXA270 User Manual
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ZEUS Technical Manual
Detailed hardware description
© 2007 Eurotech Ltd Issue D
43
Unsupported PC/104 interface features
The ZEUS does not support the following PC/104 bus features:
•
PC/104 IRQ9, IRQ14 and IRQ15 are not available.
•
DMA is not supported. Therefore, AEN signal is set to a constant logical zero.
•
Bus mastering is not supported. Therefore, do not connect any other master add-
on board to the ZEUS PC/104 interface.
•
Shared interrupts are not supported. Do not connect more than one add-on board
to the same interrupt signal line.
•
BALE signal is set to a constant logical one as the address is valid over the entire
bus cycle. Add-on PC/104 boards that implement transparent latch on address
lines LA17-LA23 are compatible with the ZEUS implementation of BALE.
•
The PXA270 PCMCIA memory controller does not support 8-bit memory read
accesses for common memory space.
•
The PXA270 PCMCIA memory controller does not support PC/104 MEMCS#
signalling, so there is no support for dynamic bus sizing.