MB86613S Datasheet, PDF (63/134 Pages) Fujitsu Component Limited. – IEEE1394 Open HCI Controller

Preliminary
(2), (3), (4)
I1
(9)
I2
z=0
I3
z=1
START
LOAD
Fig. 4.17 State Machine of Interrupt Handle for Asynchronous Packet Receive
4.2.3. Buffer- Fill Mode
This function is used when storing the received asynchronous packet into the host memory. The buffer- fill
mode is to store multiple packets into one memory in sequence. This mode allows to use the host memory
effectively although the start point of each packet can be seen from the data_length value only. This mode
requires a context program per 1 host memory. Also, the context program uses the INPUT_MORE command.
Figure 4.18 shows a reference example of buffer- fill mode. In this figure, the first packet ”packet- 1” is stored
in the host memory- 1 according to the descriptor- 1. In this case, AR- CPC stores the remaining data byte
count of host memory- 1 into resCount field of descriptor- 1. Then, the second packet ”packet- 2” is stored in
the host memory- 1, but since the host memory- 1 has no space to completely contain the packet- 2, the con-
trol ownership of context program goes to the descriptor- 2 and the rest of data of packet- 2 that can not be
stored goes into the host memory- 2. At this point, because the host memory- 1 is full already, AR- CPC also
stores ”0” in the resCount field of descriptor- 1. One packet shall not be in three or more memory(s).
descriptor- 1
INPUT_MORE
resCount=0
descriptor- 2
INPUT_MORE
resCount=0
descriptor- 3
INPUT_MORE
packet- 1
pack
host memory- 1
et- 2
packet- 3
p
host memory- 2
acket- 4
host memory- 3
Fig. 4.18 Buffer- Fill Mode (Example)
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