cxd3220r Sony Electronics, cxd3220r Datasheet - Page 51

• Manufacturer Part Number: cxd3220r
• Description: Ieee1394 Link/transaction Layer Controller Lsi For Sbp-2
• Manufacturer: Sony Electronics

7-5. ADP Setting
According to the SBP-2 protocol, a normal command block ORB (shown below) is fetched in the form of a
Block Read response packet from the initiator as a result of the target sending a Block Read response packet
to the initiator.
The Block Read response packet containing the normal command block ORB is incorporated into the ARF in
the format shown below. (Refer to the draft of the Serial Bus Protocol2 (SBP-2) for a detailed explanation
regarding the SBP-2 protocol.)
The following settings are made in the case of automatic data transfer by the ADP after fetching the ORB. To
begin with, there are the 3 modes indicated below for automatic data transfer by the ADP.
Mode 0) Page_table_present (p) = 0, Page_size = 0
When page_table_present (p) = 0, page_size = 0 are set, the ADP enters a transfer mode in which there are
no restrictions on address boundary. In this case, since the address of the initiator is directly indicated in the
data_descriptor obtained with the normal command block ORB, set the node_ID & offset_hi & offset_lo of the
data_descriptor to the Destination ID & destinationOffsetHigh & destinationOffsetLow of the ADP register. Also
set d, spd, max_payload, p, page_size and data_size. ADP transfer starts when the ADPgo bit of the ADP
control register is set to "1".
The transfer speed of request packets generated with the ADP is selected between either S100 for spd = 0 or
S200 for spd = 1.
There are no restrictions on packet size in this mode. Request packets are generated corresponding to the
data_size represented with max_payload, and data is transmitted and received sequentially. Finally, data
corresponding to the number of bytes remaining is transmitted and received with a request packet.
The following page indicates a summary of packetizing with respect to this mode.
Basic Configuration
1394Header
Footer
ORB
Block Read or Clock Response Receive Format
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
n
rq_fmt
(0)
d spd
destinationID
dataLength
sourceID
max_payload p page_size
– 51 –
command_block
data_descriptor
data_descriptor
spd
next_ORB
next_ORB
rCode
tLabel
extendedtCode
data_size
rt
tCode
acksent
priority
0
CXD3220R