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Frequently Asked Questions
Q: What is FCC DoC (Declaration of Conformity)?
A: The DoC is new certification standard of FCC regulations. This new standard
allows DIY component (such as mainboard) to apply DoC label separately
without a shielding of housing. The rule to test mainboard for DoC is to
remove housing and test it with regulation 47 CFR 15.31. The DoC test of
mainboard is more difficult than traditional FCC test. If the mainboard passes
DoC test, that means it has very low EMI radiation and you can use any kind
of housing (even paper housing). Following is an example of DoC label.
FOR HOME OR OFFICE USE
Q: What is Bus Master IDE (DMA mode)?
A: The traditional PIO (Programmable I/O) IDE requires the CPU to involve in all
the activities of the IDE access including waiting for the mechanical events.
To reduce the workload of the CPU, the bus master IDE device transfers data
from/to memory without interrupting CPU,
concurrently while data is transferring between memory and IDE device. You
need the bus master IDE driver and the bus master IDE HDD to support bus
master IDE mode. Note that it is different with master/slave mode of the IDE
device connection. For more details, refer to section 2.3 "Connectors".
Q: What is the Ultra DMA/33?
A: This is the new specification to improve IDE HDD data transfer rate. Unlike
traditional PIO mode, which only uses the rising edge of IDE command signal
to transfer data, the DMA/33 uses both rising edge and falling edge. Hence,
the data transfer rate is double of the PIO mode 4 or DMA mode 2. (16.6MB/s
x2 = 33MB/s).
The following table lists the transfer rate of IDE PIO and DMA modes. The
IDE bus is 16-bit, which means every transfer is two bytes.
A-2
AP5T
Test To Comply
With FCC Standards
and releases CPU to operate
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