SPC7281 Epson Electronics America, Inc., SPC7281 Datasheet - Page 15

• Manufacturer Part Number: SPC7281
• Description: IEEE1394 Controller
• Manufacturer: Epson Electronics America, Inc.

7.1.2 IEEE1394LINK/Transaction Controller xCSBUF Area (SRAM)
• All RAM areas are accessible from the CPU by direct
• Hardware DMA is possible to the IDE I/F for the
• HW_PageTableArea (the equivalent of 24 pages)
• The RxHeaderArea, RxORBArea, TxORB,
addressing.
RxStreamArea and TXStreamArea.
and HW_RxHeaderArea and HW_TXHeaderArea
(the equivalent of 1 header, respectively) are assured.
The RxORB and TxORB areas are usable by firmware
alone.
TXStreamArea and RxStreamArea are RingBuffers.
Even at the time of execution of data transmission/
reception according to 1394 or IDE DMA, data
among the areas are guaranteed by hardware . (The
size of each RingBuffer is variable by settings on the
TxAreaStart
0x4000C0
0x401FFF
0x4000E0
0x400000
0x400100
TxHeaderArea
+ 0x20
+ 0x40
used Asyncronouse only
AsyTxPktHdr 0
AsyTxPktHdr 1
TxHeaderArea (2 Headers)
HW_PageTableArea
HW_RxHeaderArea
HW_TxHeaderArea
HW_RxHeaderArea
RxHeaderArea
RxStreamArea
RxORBArea
(RingBuffer)
TxORBArea
(RingBuffer)
(RingBuffer)
(RingBuffer)
8KBytes
NotUsed
EPSON
TxAreaStart
• The TxStreamArea and RxStreamArea is usable as
• The Post**Ptr and Used**Ptr of the RxHeaderArea,
• By controlling the above functions from the TRAN &
+ 0x20
+ 0x30
+ 0x40
TxStreamAreaStart, TxStreamAreaEnd, and
RxStreamAreaStart.)
one StreamArea by overlaying them.
RxORBArea, TxStreamArea, and RxStreamArea
monitor the used condition in each Area.
(In the case of the Rx of 1394, the free space of the
above two is monitored and the busy_A, B, X is
controlled by hardware.)
SBP2 Control Block, a PageTable fetch and data
transfer according to SBP-2 are executable by
hardware.
RxORBAreaStart
TxHeaderAreaStart
(TxHeaderAreaStart + 0x0040)
TxStreamAreaStart
TxStreamAreaEnd
RxStreamAreaStart
(RxHeaderAreaStart)
used Isocronouse
IDE – > 1394 DMA Area
1394 – > IDE DMA Area
AsyTxPktHdr 0
IsoTxPktHdr 0
IsoTxPktHdr 1
S1R72801F00A
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