
RELEASED
DATA SHEET
PM7366 FREEDM-8
ISSUE 4
PMC-1970930
FRAME ENGINE AND DATA LINK MANAGER
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA,INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
63
Field
Description
A
Indicates if this channel is active (i.e. provisioned). If the channel
is active, the A bit is set to logic 1. If the channel is inactive, the A
bit is set to logic 0.
D
Indicates whether the linked list of packets for this channel is
empty or not. If the D bit is set to logic 1, the list is not empty and
the current TD pointer field is valid (i.e., it points to a valid TD). If
the D bit is set to logic 0, the list is empty and the current TD
pointer field is invalid.
Current TD Pointer [13:0]
Offset to the TD currently being read.
Bytes To Tx[15:0]
The Bytes to Tx[15:0] bits are used to indicate the total number of
bytes that remain to be read in the current buffer. Each access to
the data buffer decrements this value. A value of zero in this field
indicates the buffer has been completely read.
ABRT
A copy of the ABRT bit in the TD currently being read.
IOC
A copy of the IOC bit in the TD currently being read.
PiP
The Packet Transfer in Progress bit indicates that a packet is
currently being transmitted on this channel at this priority level.
NA
Indicates that a ‘null abort’ is to be sent to the downstream block
when it next requests data on this channel. The NA bit is set if a
mal-formed TD is encountered while searching down a host chain.
U
Indicates that a underflow has occurred on this channel. This bit is
set in response to an underflow indication for the downstream
THDL block and is cleared when a TDR is written to the TDR Free
Queue (or to the free queue cache).
Host TD Pointer [13:0]
A copy of the Host Next TD Pointer field of the TD currently being
read, i.e. a pointer to the next TD in the chain currently being read.
(See Figure 14)
DMA Current
Address[31:0]
The DMA Current Address [31:0] bits hold the address of the next
dword in the current buffer. This field is incremented on each
access to the buffer.
V
Indicates if the linked list of packets for this channel contains more
than one host-linked chain (See Figure 14). If the V bit is set to
logic 1, the list contains more than one chain and the next and last
TD pointer fields are valid. If the V bit is set to logic 0, the list is
either empty or contains only one host-linked chain and the next
and last TD pointer fields are invalid.
Next TD Pointer [13:0]
Offset to the head of the next host-linked chain of TDs to be read.
(See Figure 14)