Datasheet

Data-Mover Port Interface
47
SGLS139B − October 2003 − Revised April 2004 TSB12LV32-EP
Asynchronous DM Idle
(DMDONE Is High)
DMEN is 1, DMASYNC is 0
DMREADY Is High?
Asynchronous Arbitrate/Xmit
(DMDONE Is Low)
Arbitrate for Asynchronous Transmit
and Send Asynchronous Packet
Wait for Acknowledge
Ack Complete received?
Data Block Done
(DMDONE Is Low)
End of All Packets
for This Data Block?
Yes
No
No
No
DM Disabled
Re-enable via
Software
Yes
Yes
Figure 5−4. Asynchronous Transmit DM Flow Control (TSB12LV32 Transmit to 1394 Bus) (DMASYNC = 1)
5.1 Data-Mover Data Flow Diagram
The data mover has eight modes of operation. There are four modes for transmit and four modes for receive.
• Isochronous receive with automatic header / trailer removal
• Isochronous receive without automatic header / trailer removal
• Isochronous transmit with automatic header insertion
• Isochronous transmit without automatic header insertion
• Asynchronous receive with automatic header / trailer removal
• Asynchronous receive without automatic header / trailer removal
• Asynchronous transmit with automatic header insertion
• Asynchronous transmit without automatic header insertion
Definitions
• Data-mover port configured to operate in transmit mode means that the packet data is received through
the data-mover port and forwarded (unbuffered) to the link core transmit logic to be sent to the physical
layer device (Phy), which, in turn, transmits the data onto the 1394 bus.
• Data-mover port configured to operate in receive mode means that the packet data is received by the link
core receive logic from the 1394 bus through the Phy. The data is then routed by the link core to the
data-mover port without any internal buffering.
5.1.1 Isochronous Receive
In both the isochronous receive modes, the packet header information is always loaded into the header
registers in the CFR. The isochronous packet header quadlet is loaded into the header0 register at 38h and
the isochronous packet trailer quadlet is loaded into the trailer register at 48h.