SPC7281 Epson Electronics America, Inc., SPC7281 Datasheet - Page 74

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

S1R72801F00A
Receive Stream Data IDE Pointer Register
Transmit Stream Data IDE Pointer Register
70
Address
Address
0x4C
0x4D
0x4E
0x4F
This Receive Stream Data IDE Pointer Register indicates the starting address of received stream data in the
RxSTreamArea that is to be transmitted to the IDE side but not yet transmitted. Since the buffer pointer is in
Quadlet unit, the lower order 2 bits are always “0”. Also, since the buffer size is 2 Kbytes, the higher order 3
bits are always “0”.
Reading the higher order bytes holds the lower order bytes. When writing to this register, write the higher order
bytes and lower order bytes in order. (With timing of writing to the lower order bytes, the register is updated.)
This Transmit Stream Data IDE Pointer Register indicates the starting address of stream data in the
RxStreamArea to be stored following the data that was transmitted from the IDE to the SRAM. Since the buffer
pointer is in Quadlet unit, the lower order 2 bits are always “0”. Also, since the buffer size is 2 Kbytes, the higher
order 3 bits are always “0”.
Reading the higher order bytes holds the lower order bytes. When writing to this register, write the higher order
bytes and lower order bytes in order. (With timing of writing to the lower order bytes, the register is updated.)
IDE_RxStreamPtr_H 7:
IDE_RxStreamPtr_L 7: IRSP[7]
IDE_TxStreamPtr_H 7:
IDE_TxStreamPtr_L 7: ITSP[7]
Register Name
Register Name
Bit Symbol R/W
Bit Symbol R/W
6:
5:
4: IRSP[12]
3: IRSP[11]
2: IRSP[10]
1: IRSP[9]
0: IRSP[8]
6: IRSP[6]
5: IRSP[5]
4: IRSP[4]
3: IRSP[3]
2: IRSP[2]
1:
0:
6:
5:
4: ITSP[12]
3: ITSP[11]
2: ITSP[10]
1: ITSP[9]
0: ITSP[8]
6: ITSP[6]
5: ITSP[5]
4: ITSP[4]
3: ITSP[3]
2: ITSP[2]
1:
0:
R/W
R/W Transmit Packet Stream Data Area IDE Pointer
Write is ignore
Read is always zero
Write is ignore
Read is always zero
Write is ignore
Read is always zero
Received Packet Stream Data Area IDE Pointer
Write is ignore
Read is always zero
EPSON
Description
Description
H.Rst S.Rst B.Rst
H.Rst S.Rst B.Rst
0x00 0x00
0x00 0x00
0x00 0x00
0x00 0x00
–
–
–
–